To be quite honest with you, I've dealt with those very same NIC cards here at UCSD.  This year alone, I have tried...and I emphasize the TRIED...to fix a downed network connection on 6 different computers with these cards.  I hate to admit this being the Linksys fan that I am.  Those cards suck.   In the few instances that I have gotten a few to work, I used a driver disk that someone gave to me.  Let me know if you want to try these and I can probably email them to you.