Two issues with Virus TI

[solid77]

So, I'm a happy owner of a Virus TI desktop version. Better say almost happy as there are two issues bothering me:

From the very start, after updating the TIOS to 1.07 everything worked well in Cubase SX3.11. Although I've had some issues with arpeggios, the overall performance was Ok and I would say the overall setup was quite workable.
Then, one day, I've started to experience strange things. The sound coming from the Virus would crash after first 5-7 bars in Cubase. The sound routing was via USB, so I thought maybe it's the USB link that becomes overflood or something. So I've tried to have the sound routed via SPDIF. This made the whole situation even more interesting...
When I've plugged the SPDIF cable in my M-Audio FireWire Audiofile 24/96 the sound card went berserc - all the leds flashing crazily, the audio card dissapearing from the system and, of course, the sound crashing... I just thought maybe the SPDIF cables should be installed depending on the direction of the signal flow, but I haven't yet tried to flip it.

Well, given all this, I intend to have the TIOS upgraded in the weekend and also I intend to have the Virus TI sound tested in othe VST hosts (Ableton Live 5), but maybe there are gurus among you guys who could just point any hint to solve this:

1. How to get rid of the sound crash after 5-7 bars of flawless play in Cubase SX3.11? (Sound comes via USB)
2. How to establish a working SPDIF connection between Access Virus TI and an M-Audio Audiophile FireWire?