Keep alive?

I really like WinSCP and have been using it for a while. One thing that drives me nuts though is that it times out, probably due to issues with my NAT firewall, and the timeout is not detected. Other software has a keep alive setting to handle this type of thing. I realize that WinSCP is wrapping putty, which I am not an expert in using either. My typical ssh is done with a terminal client called absolute telnet, and which has a keep alive so I don't have a problem there. If this is something that needs to be set in putty somehow, a pointer in the right direction would be appreciated as well. I noodled through the docs and the options/preferences and session dialogue and nothing jumped out at me.

Found it thanks to the search. One suggestion for the site: stick a forum search box at the top so it's easily seen. I couldn't find the search until i went and read the stickied item at the top of the forum.