Firewall Blocks File Sharing in Vista

For some reasons, my laptop (Microsoft Vista) unable to share files in my office network. I can connect my laptop to my office PC (Microsoft XP) but not the other way round. Ping is okay but is the file sharing doesn't work from Vista to XP. I have tried couples of steps but no lucks. However, this doesn't happen in my home network where I can share files in 2 ways with my PC (XP).

At last, I figure out the firewall which blocks the file sharing in Vista. I do enable the file sharing in the firewall (that's why I can use it in my home network) and somehow it doesn't allow in my office network. So what I did is to disable the firewall and everything works fine. I just disable the firewall in local LAN network but not the wireless LAN network. It should be quite safe since most of the time I use the wireless LAN network.

I don't know if this is a bug but I believe so since I"m working fine in my home network. So if you encounter file sharing in Vista, for a quick fix you may want to try disable the firewall. It may works. Perhaps you have a better idea even with firewall enabled? I will try your tips then.