RAS/DUN disconnecting playing 3d games

[kusazero]

hi, anyone know why my RAS/DUN keep disconnecting when i play 3d games? even old ones (dx6)? with the same hardware config, i did not have these problems when using win2k. i am using winxp now

my hardware is as follows:

amd tbird 1G@1.4
Abit KT7E
PC133 Ram 256mb
winmodem (don't know the brand)
geforce 2 gts