intel camera freezing in Yahoo IM

First, I am not exactly sure where this post belongs as I'm not sure what is causing the problem. My husband installed the Intel Pocket camera on his Acer computer running Win 98se. Camera works fine unless he tries to access it while on Yahoo's IM. Then it freezes the whole system. I run the same camera on my Compaq Pc with ME OS; same version camera and software( Create and Share ver D 4.76), same Instant Messenger and have no problems. We thought it might be his anti virus program ( he uses McAfee ver 6.01) and have tried running it with that stopped and it still freezes. The only differences we have is he uses Netscape Communicator ver. 4.76 and I use Explorer 6. Also he connects using ATT and I have Bellsouth DSL. We've checked the drivers and installed updated Active X on his computer but none of that helped. Any suggestions on what to look at next? Have looked on both Intel and Yahoo for an answer but they don't seem to apply to his specific problem or version of the software. Am thinking the problem is occuring maybe because of his ATT connection or the Communicator?