SP2 and P2P filesharing

I’m in a peer-to-peer network, and most of my boxes are XP Pro. I have a Win98 box acting as a simple fileserver. When I install SP2, I cannot access the shared folders/files on the W98 box unless I turn off the firewall. The firewall properties show me how to allow INcoming filesharing, but not accessing network shares from within the firewall. any suggestions?
many thanks in advance.