I think motherboard may cause the problem too.
Last time, I install D-Link DFE 530 TX on IWILL VD133PL motherboard, I get blue screen everytime I start win98. In WinME, there is no blue screen but network fail to function (Delay and Slow Connection, Copy 1MB file require more than 1 min). I change the NIC to D-LInk DFE 528
and solve the problem.

Then I remove the the D-Link DFE 530 TX and install it to IWILL VX133 motherboard, so far everything works fine (not yet try WinME, because I don't want to use WInME anymore, now I only use Win98SE and Win XP Pro).

WinME is too bad. :-(