NASLite Network Attached Storage

I had to temporarily change my router, so had my NASLite box disconnected for a few weeks. I restored the original router, hooked up the NASLite box, restarted it and everything works fine *except* that I can't access it from my laptop running XP Pro! Two other laptops (MacBooks with XP Home) can access it just fine! From my laptop I can telnet into it, and I can access it via IE and its IP address, but I can't get to it as a file server! I've double and triple checked that the Workgroup is correct (it is) - any other ideas?