My MOTU 2408MKIII works perfectly well with every computer I try it on but my Sony VAIO PCV-RZ30GN2. No matter what I try, it will not recognize the MOTU card. What gives?
Despite the title, your post does not seem to be related to Vegas at all. I would have thought your chances of getting help on this problem were higher at a MOTU or Sony forum (but I hope you get lucky).