This occurred in one of my private repos, I don't have tested it explicitly, but I think this is a common problem.
Steps : 1. Choose to strip a changeset on a branch which does not include the "tip". 2. Go to Admin (click Repo management) 3. Type the changeset number or hashid to the text box and submit it. 4. Next screen will show the preview of changesets which are going to be stripped. There are more changesets than these should be there! 5. Verify the action with the password. 6. Look at the result ... the action behaves correctly, by stripping the appropriate changesets. So the problem is on step 4. (The preview of stripped changesets is buggy)
I hope this is helpful ;)