That menu item does indeed exist on my installation too (newest dapper, RB 0.9.3.1). I missed it before, I guess, because it's grouped together with the cut&paste operations.
-- No menu entry for deleting from library https://launchpad.net/bugs/42386 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs