I tried cycling the power of my modem and D-Link router as part of troubleshooting with Cyberduck, and unfortunately it didn't work for me. What finally did work was to use FileZilla. I had to copy my file over to my main sytem hard drive before transferring via FileZilla, which I didn't really want to do, but it worked! So long Cyberduck, for now.
Interesting..I use Cyberduck and upgraded to Mountain Lion. Immediately stopped working. It will upload 1 file and then enters the Network Failure mode. Close down cyberduck. Repoen...transfers first file and then error. All ftp programs are acting the same way for me.
Double interesting...my mac book pro is on Snow Leopard with cyberduck and no issues using the same network and modem
It is definately something in Mountain Lion causing the issue....but what?
rbrowser specifically for mountain lion took all my problems away. Its not that mainstream but works.
Going back to cyberduck/filezilla/transmit problem reappeared