Repair SVN Checksum

I'm using subclipse in Flex Builder 3, and recently received this error when trying to commit:

svn: Checksum mismatch for '/Users/redacted/Documents/Flex Builder 3/path/to/my/file.mxml'; expected: 'f8cb275de72776657406154dd3c10348', actual: 'null'

I worked around it by:

1. Committing all the other changed files, omitting the troublesome one.
2. Copying the contents of the trouble file to a TextMate window
3. Deleting my project in FlexBuilder/Eclipse
4. Checking my project out fresh from SVN
5. Copying the text of the trouble file back in from the TextMate Window
6. Committing the changes.

It worked, but I can't help but think there's a better way. What's actaully happening to cause the svn:checksum error, and what's the best fix.

Maybe more important -- is this a symptom of a greater problem?