An update to my previous problem with checking into SVN.  I had the same problem just now:

$ svn commit -m "message"
Sending        debian/control
Transmitting file data .

Committed revision 9488.

Warning: post commit FS processing had error:
sqlite[S5]: database is locked

I SSH’d into the server to try and figure out the problem.  I then stumbled across this post on the SVN mailing list.  Checking the rep-cache.db, it has two commits less than what the current revision number is, which would match up with my two failed commits, so that seemed suspicious.  I then figured out if some process had the rep-cache.db open at all:

$ lsof | grep rep-cache

As it turns out, Atlassian Fisheye had a bunch of connections open to this database for some reason.  I restarted Fisheye to kill all those connections, so we will see if that fixes the problem.  Note that this is also running an old version of Fisheye(3.2.3), so it could be a problem with just this version.