Saaya, are we sure it worked fine before? Multiple vendors drivers generally don't play nicely together, which usually causes all kinds of stability issues. Could you imagine the sheer number of non-computer knowledgable people calling NVidia complaining when the 2 drivers together cause graphical corruption and they blame NVidia because before they added the geforce card for physx the system worked fine? You worked in CS before, you know it would happen.

If we have a completely impartial judge to test this out, see if it worked without issue before in all physx enabled titles, then we can make that call. I'd actually be interested in seeing those numbers myself!