XP freezes sporadically with LAN access

I have a Windows ’98 box and a Windows XP with a Linksys router between them. Both machines have 10/100 MBPS LAN cards.

I use ‘computers near me’ to find the ’98 machine.
I then drag 200+ files over and as they are transferring the XP will hang, It has to be rebooted. Any ideas?