svn hangs when tunnelling through ssh

I have a strange behavior when trying to use svn over ssh tunnel. Environme开发者_StackOverflow社区nt: server running Ubuntu9.04, client running Debian Lenny Symptoms: svn hangs both on client and server on some (but not all) long operations. E.g. svn log always works, committing some files may work, othes - don't. What I tried:

• svn+ssh:// protocol
• creating a tunnel for 3690 port through ssh and using svn://
• creating a tunnel for 80 port through ssh and using http:// (with apache and mod_dav_svn on server)

All those with the same result. Updating svn to latest build doesn't change anything. It seems to be some ssh issue, but ssh itself works perfectly.

Any thoughts?