PC Hanging on exit from game

[JamWheel]

Hi All,

This is a bit of a peculiar problem. The game plays beautifully - well done

Once I have been playing for a significant length of time (this issue doesn't happen after playing for 2 minutes) when I exit IL2 back to windows I am left with a white steam window and the circular egg timer.

Steam.exe is hanging and so is Explorer.exe. I can launch task manager and go to the processes tab but neither respond to being killed (every other process is killable). The only thing I can do is turn off my PC the bad way... not good.

I have tried a few "Run as Administrator" type changes but none have helped it seems.

Has anyone else had this issue?
Can anyone give me any diagnostic tests to do?

Drivers etc are up to date.

Windows 7 Pro 64 bit
Intel i7 2600k @ 3.4ghz
AMD RADEON™ HD6950
16GB RAM
Intel SSD OS Drive

Please help!