I had the same problem
The only finger I could point it was at windows millenium
I would have a 100mb connection and the the lights 100mb lit on both cards for both my 700mhz XP machine and 700mhz ME machine
I would start up millenium and begin a big file transfer adn itw ould begin fast and tell me about 6 minutes left and if I left it for 5 minutes, it would tell me something like 4 hours remaining.
I upgraded to win2k and never had a problem.
NOw i"m back to Millenium, and when I try to transfer multiple files, say like 30 mp3's, it'll try to transfer them ALL at once!
Stupid Mistake Edition of windows. That's the only complaint I have for ME. Well 2.
The removal of DOS mode and crappy network stuff. 98SE was much better