I know that not everybody seems to have timing glitches when using arpeggiator via Virus control plugin and using analog outs! Maybe I’m wrong, because not everybody is using the Virus in the same way 
Ok, I don’t have the possibility to use a powerful PCI-USB card, which might be a solution, because I use a notebook (2x2.2 Ghz, quick harddisk, Windows XP and therefore 3 GB RAM). I think that’s matter and right there are some peripheries I’m using via USB too. However, using the Virus Ti Snow with Virus control, you can use all the USB outs without timing problems if you arrange your Midi sequence in the sequencer host you are using (Ableton Live 8.2.1). I tried all possibilities (Live mode on/off, latency compensation on/off, manual latency time correction (but latency is not the problem I’m talking about), different buffer length with Edirol FA 101 Firewire I also tested.
If you want to use arps perfect in time using analog outs, then you must use the virus like a hardware synth without software plugin. Try to use the internal clock, which is stable independent how many effects you are using in your patch or changing many parameters in real-time!
The disadvantage is for example, that it is impossible to record changes of LFO timing (1/4-1/8-1/16…) to midi, only rate without Clock divider! And it isn’t as handy as controlling the virus via software.
Would it be possible to integrate the opportunity of changing the clock to internal, selecting the BPM you need via Virus Control? I think the answer is no. Maybe you ask why it should be necessary.
I hope you understand what I mean because of my unprofessional English skills. Many people are suffering the time glitches independent from soundcard, peripheries, MAC or PC, Host Ableton, Cubase, Logic whatever, Virus OS 3 or 4 or 4.5.
In any situation the virus have to correct its clock which is received from the host midi clock, and of course there is sometimes a lot of traffic and sometimes very low, that is a challenge for the time correction. An internal virus clock for the sequences in the virus control and the rest can be kept as it is could be the main solution for everybody.