In earlier KDevelop versions, I remember that right-clicking the KatePart "icon border" showed a context menu where you could set either a breakpoint or a bookmark. It also let you choose which of the two would be set by single-clicking the icon border. Now, clicking the border sets a breakpoint, and right-clicking does nothing. I highly suspect this problem was introduced in kdevplatform:5a80aff6. I'm using the 4.5 git branch (kdevplatform a0976070, kdevelop ab1a54a8).
*** This bug has been marked as a duplicate of bug 267806 ***