Usb problem with Virus ti desktop

Hi People!

I'm using a virus ti serie1 desktop connected usb with my sony vaio, I'm having big problems when I try to export a midi loop to audio, 90% of the case he show cpu overload and the export go in crash, I have setup good my edirol ua 25 audiocard, already tryed to set up the buffer size in different ways, I can't remove this problem! I work with cubase 5 and when I press F12 for check the performance vst it show that line in the middle, I'm not using so many plug-ins. What do you suggest?
Thnx for support
Alex

Sorry don't understand what you mean by offline mode, can you explain?

I'm using not a daw but a sony vaio laptop, I make an example, I put in solo the midi virus sound than I press export to audio, it alwais ask in wich format you want to bounce, the folder destination, the bit, the sample frequency that I put to 44.100, 24 bit, but after maximum the 20 % of the export it show this cpu overload and can't export in audio even if is a very little loop! Are there any others wais for bouncing in audio using the vst, otherwise I start to use it plugged via 2 midi cables and 2 jacks connected to the inputs of my audiocard! HELP!!!!

Yeah I do exactly that, EXPORT IN REAL TIME! but I told you the export goes in crash after a couple of seconds!

So I understoddd that it depends on my laptop usb power that problem for export in real time, can't do nothing now, only way to use my old good desktop pc and let the vaio only for liveset! anyway thnx for try to help me