I think Comodo Firewall is blocking my xp pc from file-sharing with this Win7 pc

I have Win7 with Comodo on one pc, and another laptop with XP. I am trying to set up file and printer sharing, but I think Comodo may be blocking my XP computer from seeing the Win7 computer.

Using my Win7 computer I can easily get files from the XP computer, BUT I can’t do the reverse from the XP pc?! The XP computer has icons in the network connections area for the Win7 pc but when I double-click them to open them I get an error saying I don’t have permission to access the files - and I don’t use a password or anything on the Win7 pc.

I have gone through my Win7 pc in the Advanced Sharing Settings and turned on Discovery, file and printer sharing, public folder sharing, and I turned off Password Protected Sharing, and am allowing Windows to manage homegroup connections on both Home and Public sections…

Is there something I am missing?

Thanks all!