Last week, I was trying to connect to an SVN repository over SSH, using TortoiseSVN and Putty. I found a the faq on how to configure everything and checked it to make sure I was doing everything right.
I tried to connect. TortoiseSVN asked for my certificate password. And then, nothing. I could see that indeed TortoiseSVN was connecting to the SSH server; but just sat there doing nothing. I had to kill it several times to abort the connection.
I had already tried connecting using Putty directly, and that seemed to work, so I kept checking my settings, but for the life of me I couldn't figure out what the deal was.
Eventually, I figured out what the deal was:
See that "Don't start a shell or command at all" checkbox? Yep; that should NOT have been checked, as it prevented the server from starting svnserve to handle the SVN connection. Don't know why I had checked it before, but everything worked as soon as I removed it from my Putty profile.