Hi,
I've just sent this to support, but I thought I'd reproduce it here so that anyone with the same issues know that they're not alone.
Since I sent support an email, I've also found out the TI may not be the only driver with this problem (see http://stackoverflow.com/a/20407016 ), it sounds like it might be significant work to fix 
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The latest 5.1.0.0 driver is causing problems in OS X Yosemite with some CoreAudio software, especially (and strangely) when the Virus is *NOT* connected to the Mac, or NOT selected as the default CoreAudio device in Audio/Midi Setup.
Just having the driver loaded causes issues, such as : the new Facetime feature that allows to make calls on a Mac through an iPhone, fails each time.
After some digging around in system logs (I'm a software engineer) I suspected that the Virus driver might be the cause of these issues : I've uninstalled it and indeed all went back to normal.
Here are some of the logs I get in the OS X console when trying to make a call on the Mac through the iPhone, with the Virus *POWERED OFF* :
17/10/2014 16:02:42,935 callservicesd[17016]: Enter CreateAudio
17/10/2014 16:02:42,936 callservicesd[17016]: CreateAudio: CurrentprocessName callservicesd PGKernelDeviceVirus
17/10/2014 16:02:43,879 callservicesd[17016]: Failed to get the bundle id
17/10/2014 16:33:21,762 callservicesd[37439]: CurPID=37439, curUID=501 process=NO_NAME
17/10/2014 16:33:21,763 callservicesd[37439]: CurrentprocessName is callservicesd
17/10/2014 16:33:21,763 callservicesd[37439]: Found a device of class PGKernelDeviceVirus (won't write), result 00000000.
17/10/2014 16:33:21,765 callservicesd[37439]: fwUpdaterActive: No updater detected
17/10/2014 16:33:21,765 callservicesd[37439]: before m_cTreadStartStopSemaphore.wait
17/10/2014 16:33:21,766 callservicesd[37439]: after m_cTreadStartStopSemaphore.wait
17/10/2014 16:33:21,766 callservicesd[37439]: UID= VID_133E_PID_0815_BUS_80110000
18/10/2014 00:03:32,295 sandboxd[6929]: ([8469]) FaceTime(8469) deny iokit-open AudioUserClientVirus
18/10/2014 00:04:31,954 coreaudiod[396]: PtASPlugInAddDeviceClient Bundle Ref: com.apple.FaceTime, clientID 871
18/10/2014 00:04:31,967 FaceTime[8528]: Enter CreateAudio
18/10/2014 00:04:31,967 FaceTime[8528]: CreateAudio: CurrentprocessName FaceTime PGKernelDeviceVirus
18/10/2014 00:04:32,074 FaceTime[8528]: getHogID failed
18/10/2014 00:04:32,074 FaceTime[8528]: CurPID=8528, curUID=501 process=NO_NAME
18/10/2014 00:04:32,074 FaceTime[8528]: CurrentprocessName is FaceTime
18/10/2014 00:04:32,075 FaceTime[8528]: Found a device of class PGKernelDeviceVirus (won't write), result 00000000.
18/10/2014 00:04:32,075 FaceTime[8528]: Could not open device - exit
18/10/2014 00:04:32,618 sandboxd[6929]: ([8528]) FaceTime(8528) deny iokit-open AudioUserClientVirus
FaceTime(8528) deny iokit-open AudioUserClientVirus
Process: FaceTime [8528]
Path: /Applications/FaceTime.app/Contents/MacOS/FaceTime
Load Address: 0x108da9000
Identifier: com.apple.FaceTime
Version: 2142 (3.0)
Build Info: 6-FaceTime~2142000000000000
Code Type: x86_64 (Native)
Parent Process: launchd [1]
Date/Time: 2014-10-18 00:04:32.076 +0100
OS Version: Mac OS X 10.10 (14A389)
Report Version: 8
Thread 0:
0 libsystem_kernel.dylib 0x00007fff8f0a352e mach_msg_trap + 10
1 IOKit 0x00007fff8f2c9dfc io_service_open_extended + 144
2 IOKit 0x00007fff8f26dd91 IOServiceOpen + 45
3 de.access-music.virus_ti 0x000000010d381093 DriverConnection::ioOpenConnection() + 115
4 de.access-music.virus_ti 0x000000010d38100a DriverConnection::DriverConnection(unsigned int) + 138
5 de.access-music.virus_ti 0x000000010d388c91 PGOSXDevice::PGOSXDevice(AudioHardwarePlugInInterface**, DeviceManagerClient*, unsigned int, OSXDeviceManager*) + 65
6 de.access-music.virus_ti 0x000000010d388c43 PGOSXDevice::PGOSXDevice(AudioHardwarePlugInInterface**, DeviceManagerClient*, unsigned int, OSXDeviceManager*) + 51
7 de.access-music.virus_ti 0x000000010d37ac90 OSXDeviceManager::notifyNewDevice(unsigned int) + 80
8 de.access-music.virus_ti 0x000000010d37ae8b OSXDeviceManager::ServicePublished(unsigned int) + 27
9 de.access-music.virus_ti 0x000000010d37adef OSXDeviceManager::ServicesPublished(unsigned int) + 79
10 de.access-music.virus_ti 0x000000010d37a6b7 OSXDeviceManager::ScanServices() + 71
11 de.access-music.virus_ti 0x000000010d37a5ae OSXDeviceManager::OSXDeviceManager(AudioHardwarePlugInInterface**, DeviceManagerClient&, bool) + 2174
12 de.access-music.virus_ti 0x000000010d379d24 OSXDeviceManager::OSXDeviceManager(AudioHardwarePlugInInterface**, DeviceManagerClient&, bool) + 52
13 de.access-music.virus_ti 0x000000010d37b3cb PGAsioDriver::onInitialize(unsigned int) + 107
14 de.access-music.virus_ti 0x000000010d37c12b PGAsioDriver::onInitializeWithObjectID(unsigned int) + 27
15 de.access-music.virus_ti 0x000000010d37c103 AudioDriverInitializeWithObjectID(AudioHardwarePlugInInterface**, unsigned int) + 35
16 CoreAudio 0x00007fff922e335f HALPlugInManagement::CreateHALPlugIn(HALCFPlugIn const*) + 1263
17 CoreAudio 0x00007fff922e2450 HALPlugInManagement::Initialize() + 306
18 CoreAudio 0x00007fff922e024f HALSystem::CheckOutInstance() + 147
19 CoreAudio 0x00007fff922fb668 AudioObjectGetPropertyDataSize + 126
20 AVConference 0x000000010ce8ffb5 +[AVInternalDeviceList newDeviceList] + 67
21 AVConference 0x000000010ce90337 -[AVInternalDeviceList init] + 93
22 AVConference 0x000000010ce90a1e -[AVAudioDeviceList init] + 87
23 AVConference 0x000000010ced0614 -[AVAudioClient init] + 87
24 IMAVCore 0x0000000108f2ee45
25 IMAVCore 0x0000000108f2ed89
26 libdispatch.dylib 0x00007fff8be63c13 _dispatch_client_callout + 8
27 libdispatch.dylib 0x00007fff8be63b26 dispatch_once_f + 117
28 IMAVCore 0x0000000108f2ed43
29 IMAVCore 0x0000000108f084f0
30 TelephonyUtilities 0x00007fff885505b9 -[TUCallCenter initWithDaemonDelegate:] + 1429
31 TelephonyUtilities 0x00007fff8854fe1f __50+[TUCallCenter _sharedInstanceWithDaemonDelegate:]_block_invoke + 51
32 libdispatch.dylib 0x00007fff8be63c13 _dispatch_client_callout + 8
33 libdispatch.dylib 0x00007fff8be63b26 dispatch_once_f + 117
34 TelephonyUtilities 0x00007fff8854fdea +[TUCallCenter _sharedInstanceWithDaemonDelegate:] + 98
35 FaceTime 0x0000000108ded299
36 AppKit 0x00007fff917a8a49 -[NSCustomObject nibInstantiate] + 346
37 AppKit 0x00007fff917a888b -[NSIBObjectData instantiateObject:] + 309
38 AppKit 0x00007fff91c8ada1 -[NSIBObjectData nibInstantiateWithOwner:options:topLevelObjects:] + 452
39 AppKit 0x00007fff9179d055 loadNib + 384
40 AppKit 0x00007fff91d0b020 +[NSBundle(NSNibLoading) _loadNibFile:nameTable:options:withZone:ownerBundle:] + 313
41 AppKit 0x00007fff9179c725 -[NSBundle(NSNibLoading) loadNibNamed:owner:topLevelObjects:] + 201
42 AppKit 0x00007fff9179c4f1 +[NSBundle(NSNibLoading) loadNibNamed:owner:] + 344
43 AppKit 0x00007fff91797f59 NSApplicationMain + 605
44 libdyld.dylib 0x00007fff879425c9 start + 1
Binary Images:
0x108da9000 - 0x108e9afff com.apple.FaceTime (3.0 - 2142) <c9d2e404-be45-3975-8e91-698bd27fabe1> /Applications/FaceTime.app/Contents/MacOS/FaceTime
0x108ef1000 - 0x108f50fff com.apple.imavcore (10.0 - 1000) <e69fe779-0254-3f7b-8689-8e55ae06ce2f> /System/Library/PrivateFrameworks/IMAVCore.framework/Versions/A/IMAVCore
0x10cdd2000 - 0x10cf33ff3 com.apple.AVConference (3.0 - 734.4) <1ef03188-706d-3c08-8d22-bc09ee145708> /System/Library/PrivateFrameworks/AVConference.framework/Versions/A/AVConference
0x10d368000 - 0x10d3a8fff de.access-music.virus_ti.util.hal (3.3.0) <b08d36ed-c9de-3b3b-91d5-a627e7295263> /Library/Audio/Plug-Ins/HAL/de.access-music.virus_ti.plugin/Contents/MacOS/de.access-music.virus_ti
0x7fff8793f000 - 0x7fff87942ff7 libdyld.dylib (353.2.1) <19faf435-c165-3374-9def-d7bba7d61db6> /usr/lib/system/libdyld.dylib
0x7fff88541000 - 0x7fff8856fff7 com.apple.TelephonyUtilities (1.0 - 1.0) <72b8d7a4-c6be-330e-942b-c90f824cdc89> /System/Library/PrivateFrameworks/TelephonyUtilities.framework/Versions/A/TelephonyUtilities
0x7fff8be62000 - 0x7fff8be8cff7 libdispatch.dylib (442.1.4) <502cf32b-669b-3709-8862-08188225e4f0> /usr/lib/system/libdispatch.dylib
0x7fff8f092000 - 0x7fff8f0affff libsystem_kernel.dylib (2782.1.97) <93e0e0a9-75b6-3904-bb4e-4bc7c05f4b6b> /usr/lib/system/libsystem_kernel.dylib
0x7fff8f268000 - 0x7fff8f2d9ff7 com.apple.framework.IOKit (2.0.2) <ed3b0b22-aacc-303b-bfc8-20ecd1af6ba2> /System/Library/Frameworks/IOKit.framework/Versions/A/IOKit
0x7fff91795000 - 0x7fff922d6fff com.apple.AppKit (6.9 - 1343.14) <1732c412-257b-340e-8863-b8162d4eb2e2> /System/Library/Frameworks/AppKit.framework/Versions/C/AppKit
0x7fff922df000 - 0x7fff92330ff7 com.apple.audio.CoreAudio (4.3.0 - 4.3.0) <af72b06e-c6c1-3fae-8b47-af461cae0e22> /System/Library/Frameworks/CoreAudio.framework/Versions/A/CoreAudio