This happens because BreakpointsSidebarPane is now created lazily and it does not add all uiLocations that are already available when it is created.
Patch to follow.
Created attachment 165996 [details]
Comment on attachment 165996 [details]
Clearing flags on attachment: 165996
Committed r129775: <http://trac.webkit.org/changeset/129775>
All reviewed patches have been landed. Closing bug.