As I read your post it appears that there is some intermittent wireless problem that probably had (has) nothing to do with the firewall per se.
Are there other wireless networks and devices around? I.e., a dorm, apartment, nearby neighbors.
Need to do some testing to narrow down the possibilities.
Change the wireless frequency and channel being used.
Try moving the computer closer to the wireless router to see if that helps. Temporary relocation for testing.
Try wireless adapter antenna extensions if you have them. Try re-orienting the antenna.
If using a USB wireless adapter put it on the end of a USB extension cable so the adapter can be easily raised higher or otherwise moved about to improve reception.
See what, if anything, can be made to work.