sound diver midi failure

[Mind Bender]

I have a strange problem when i edit my library with the soundiver, midi cables are correctly connected, my viruse indigo's Low and hi page are both to sysex and the software seem to recognize the machine.

I begin to work, I can send and reviece data correctly to the virus but all of a sudden, after a few operations, the sounddiver tellsa me there is a communication problem and dosen't see the virus anymore.

I then quit and restart sounddiver and all is fine !, for a few operations

any hint of what might be the problem ??