Networking with XP

I have three machines on my LAN, a Win2K, an XP and a Win98 box. I can access any network drive and the contents of its folders from the Win2k or the Win 98 machine within microseconds, but the WinXP box always takes sometimes in excess of 5 minutes to display the contents of a folder on the network. Ok, i have a internal hardware firewall but that shouldn’t effect me internally. Does anyone have any tips on what I should check on to get slightly better performance when accessing network folders from my XP machine??!?