FTP Timing Out

I've been struggling with an FTP problem for a while now and I'm still not sure what is wrong. I have an FTP that is just a simple batch file with a few FTP commands. I'm attempting to pull down about 120 files or so with a total size of about 100 meg. (files range from 500 k up to 1.5 meg). The problem is that the FTP times out. I connect just fine, I can pull down several files, then without an apparent reason, the process stops.

I don't know much about the network setup here, but I am going through a firewall. If I bypass the firewall, everything works perfectly so I'm assuming there is something going on with the firewall.

While troubleshooting, I downloaded cuteFTP to do some testing. With both PORT and PASV I had the same results - a timeout after pulling down several files.

I get the same results regardless of where I try to connect to pull files from (I tried 3 different sites - one microsoft). I even tried the ftp between two servers on our network - pulling from one to the other with the firewall in between and got the same results.

I'm confused because it works for a few minutes. Sometimes I get one or two files down, sometimes 5, sometimes 10 before it quits on me. Any ideas on what I can look at or what can be causing the issues?

Any help is greatly appreciated!