Autoassigned IP address

I have a laptop with 98SE loaded (fresh install). I insert a 10/100 3Com NIC(have tried several). The card registers and boots up fine and everythig is great as long as I am attached to the network. However, this is a laptop and therefore will seldomly attached to a network. As soon as it is detached the boot up is extremely slow and when I run WinIPcfg it shows an “autoassigned IP address” that is not from our pool. I click release IP and it will not release. Anyone have any thoughts on this matter???