Yeah, when I find myself drifting towards the 'maybe it is a bug in the compiler/OS/debugger' territory I know it is time to take a break from the debugging as it is rarely true[1]. Nice to see it occasionally happens :)

[1] I work on Visual Studio so I have found compiler/debugger bugs as I am generally using 'in development' bits, but far more often than not the bug turns out to be mine and mine alone :)