I had recently upgraded TortoiseSVN to 1.4.0 (then had to upgrade my other clients since the updated BerkeleyDB it uses became incompatible), and I had made some temporary changes to a file in one checked out directory and just wanted to revert the file back to what it was. I forget the exact error, but it was something like "Can't get text for file: ...." but the file name was some other file that did not have any changes to it. So I thought I'd just delete that file, and then do an 'svn update'. Then I got an error message that was like Can't copy 'XXX.svn-base' to 'XXX.tmp': The system cannot find the file specified.", and in the bookkeeping directories under the '.svn' directory (prop-base and text-base) the files for that file did seem to be missing. An 'svn cleanup' didn't help. That file was added months ago, and had never changed (at least that's what 'svn log' says), and it didn't seem to be a case-sensitive issue like the link for the error message above said it was.
I finally gave up trying to fix it, and just checked out the directory again, which I didn't really want to do, since it was a fairly large directory (~250MB), and it takes a while to check out.
