I get this constantly:

The firewall has blocked Internet access to your computer (TCP Port 6346) from 206.172.159.100 (TCP Port 3191).

I want others to be able to download from my system. What gives? I have read and tweeked but to no avail.... Help!!

From what I understand, it is still possible for other people to download from you (assuming that they aren't behind a firewall as well.) The software handles firewalled IPs by sending a push request to you, which means your system will attempt to initiate the transfer, rather than the person who wants the file (whose normal requests are blocked by ZoneAlarm.) Of course, this doesn't work if their firewalled as well, because they're firewall will block the transfer initiation attempt made by your computer.
Basically, a lot of people can still download from you, but a few can't. I'd suggest disabling the pop-up warnings in Zone Alarm, because they get really annoying pretty quickly (especially since you will often get connection requests for a significant period after logging off gnutella)

If you are using Gnotella try checking the "firewalled" option so that you will initiate a push instead of them trying to get a file.

- Rob

or have a search for zonealarmpro, the professional version should sort out the problem

Have you tried to give Gnutella the right to act as a server? If that doesn't help you could switch the internet security to medium (or even low if it's necessary). I think that should work because then Zone Alarm wouldn't block the internet traffic but it's less secure, it would be much better if it's enough to give Gnutella server rights.
GA

I use standard (free) ZoneAlarm and can download files as well as other can download from my computer...

just look if you allowed your GnuTella Client to "act like a server"