subversion: commit failed
 

I've just set up a svn-repository. Worked fine until I tried and do a checkout, then commit, via ssh from another host.

To do the checkout, I issued the following command:
"svn checkout svn+ssh://hostmachine/path/to/repos/trunk project"

After the modifications I issued "svn commit", and then
the following error occured (if I'm not mistaking):
"svn: No transaction named '3' in filesystem '/path/to/resp/db'

Also, I logged on to the server where the respository resides, and issued
"svn up",
and got the same error as the previous.

How can I fix this error, and what did I do wrong in the first place?