I ran into the same issue as described exactly here: http://email@example.com/8177435.html I merged a set of changes down to my trunk working copy, and when I tried to commit it would fail saying my adds already existed in the repository when the definitely did not. I worked around this by reverting the adds, checking in most of the merge, readding the adds and checking them in with a second revision. Ugly, but I was able to work around it. Though it wasted a good bit of my time figuring it out.
Original issue reported by evanleonard