sshfs transfer issues

[Guest]

[uncle hammy]

I have just set up my Endian box, which is replacing a Linksys router with dd-wrt.  I have added an outgoing rule to Endian for ssh, and from the a PC in the Green Zone, I am able to ssh into a remote server that I perform backups to.  I am able to mount a local folder via sshfs to the remote server, and am able to copy files (one at a time) to the remote server through the sshfs mount.  However, when I try to do a big backup (using rsync, or even cp), I am only able to transfer a file or two, then everything just stalls.  If I remove the Endian from the picture, and plug my computer directly into my DSL modem, I have no issues. 

I did also have this same issue with the dd-wrt router.  It's also worth noting that I had a  set me up with ssh access to one of his servers, and when if mount the directory via sshfs to his server, I have no troubles going through Endian to do transfers.  However, because the owner of the server space I am trying to use has no other clients with issues, and because I have no issues with a direct connection, he is claiming the issue is on my end with Endian (or dd-wrt too, I suppose).

Anyone have any ideas what could be causing this?

Thanks