Audio driver failed ?

[dione]

I have a strange problem with my Virus TO desktop...:

When i open a Cubase project i was working on,the Virus Control isn't working (and no sound from TI)...when i open it i get the following message :

"Audio driver failed

The audiodriver failed to start or is not installed.
This can happen if you have connected too many usb devices.
Also try to install the Virus TI software again."

I didn't change anything in my usb set-up...and the driver is working fine,but i tried installing it again anyway,no change...

The crazy thing is that if i open another project,the TI (and Virus Control) works fine...so it seems there's just one project giving me this problem ? I tried everything : taking Virus TI out of the VST instruments list,saving under another name,making a back-up project,the whole shabang...

I'm on Windows XP home,Cubase 5.0.1. and Virus TI version 3.0.3.00,Audio driver version 2.8.14.0

Any tips ?