Commit failed (details follow): File 'your_file' is out of date

I have no idea, but all of a sudden I got this svn error during my commit.

My solution is roughly the following.

cp your_file your_file.bak
svn revert
svn update
cp your_file.bak your_file
svn commit
rm your_file.bak

A nice workaround that helped me move on.