iOS: C++ debugging on device has breakpoint issues and shows disassembly

Debugging on my device (iPod with iOS 6.x) has a few issues. In most of the debugging sessions, I land in the disassembly view, and the contents of the breakpoints view look suspicious.

Once, I got into a state where the editor window and breakpoint list displayed an undeletable breakpoint.

Happens in C++ debugging mode and "mixed" mode. Latest OS X, latest Xcode.