i have the same problems, however, i think it is our fault because we are not sticking to the required hardware for the Aja card, ie. the xeons, dual opterons, proper mobo, and the quadro, as well as raid requirements.
I have had nothing but crashes int he oddest times, slow alt tabbing, etc. but my specs are:
opteron 170, asus a8n sli, 1.34tb raid 0 (media drive), 400gb raid 0 (system os drive), both raids are on 7200rpm drives, ati 1900xt..
I think the best solution is to stick to aja’s recommended specs