Yes, i'm having exact same problems when I run this command (for capistrano rails pull).
dh-server$ svn export svn ssh://me@homebox/path/to/project
Killed by signal 15.
They claimed upgrading to their overpriced PS service would fix this, but it hasn't. I don't recommend upgrading if that is what they tell you -- it won't solve this issue.
I've tried the same command from other remote servers to my box @ home, and it works fine...I believe they are killing svn ssh commands, just a matter of finding the right person who can fix it.