i have this problem too.. i had the same problem on my old computer. i had a 1.2 athlon, 768 megs sdram, windows xp corporate, logitech 3000, 400 gigs harddrive… newest version of yahoo.. whenever i tried to use the cam it would freeze yahoo, and lock my system, id have to reboot to do anything.. the same thing when i try to send a file, there will be about a 30 second lag before the window shows up, and yahoo will freeze until then..

now i got a 2.7 athlon, 512 DDR, windows xp corp, logitech 4000, 520 gigs harddrive, and an even newer version of yahoo..

when i go into yahoo it doesnt even recognize the camera.. but the mic works fine, and the cam works great in every other camera/video type software, just not yahoo.. yahoo doesnt even recognize a camera.
and i still get the lag when i try to send a file..