I started getting this messaage
Sending wiscrowd/mod/freerider/templates/index.htm Transmitting file data .svn: Commit failed (details follow): svn: Base checksum mismatch on '/trunk/contrib/drchuck/wiscrowd/mod/freerider/templates/index.htm': expected: 1c2fe4a8f013f8af2729280d89567095 actual: 2ea55328bc430c0f6e738303e4393f3b svn: Your commit message was left in a temporary file: svn: '/Users/csev/dev/cloudcollab/contrib/drchuck/svn-commit.4.tmp'
The solution was to make a copy of the file, delete the file from svn and then re-add it.
This loses history – but is quick and dirty when you are in a hurry.