I have exactly the same problem, I've tested in normal and passive modes with no success.
The file is transferred totally but if you have a bunch of files, the ftp client stucks in the first file and it's neccessary to abort connection to continue.
The only thing I changed from configuration was Ip Filters:
Maximum Ports: 4096
TCP Timeout (in seconds): 160
UDP Timeout (in seconds): 160
Posted: Tue Mar 20, 2012 1:51 Post subject: Can't believe it took this long to find a solution
I was having an identical issue, and thought it was a dhcp lease timeout issue, which it turned out it was not. Apparently, my very recent DD-WRT build (DD-WRT v24-sp2 (04/13/11) std-usb-nas - build 16785, for a Linksys E3000) defaulted the TCP and UDP Timeouts to a crazy value:
"300 600 120 60 120 120 10 60 30 120"
I was able to fix the issue by changing the TCP and UDP timeouts to something a bit higher than the longest time it would normally take me to upload a very large file to my website hosting, which was about 10 minutes or so.
The following settings fixed my issue:
1. > Administration > Management tab > IP Filter Settings (adjust these for P2P) > TCP Timeout (in seconds) > 600
2. > Administration > Management tab > IP Filter Settings (adjust these for P2P) > UDP Timeout (in seconds) > 600