Just found a solution to a small but irritating issue, so I thought I'd share ...

If you set a breakpoint in your code and then later remove the breakpoint, often the code execution still gets stopped at that point as if the breakpoint still exists.

The way to clear it is to press [Ctrl-Shift-F9], which clears all breakpoints. Of course I thought I'd done that by removing the breakpoint earlier, but obviously I was just being optimistic!