Game crashing while starting another application

[Wheelfg]

Details:
The game will just crash every time I leave it on background starting another application (let's say another game, or everything else). Sometimes could just crash by hitting Ctrl - Alt - Canc without closing it with Task Manager. No error messages.
That's bad since I can't do anything else while, for example, leaving my pg logged selling through Bazaar.

Frequency:

Always

Platform:

PC

Windows 7 64 bit

Amd FX 8320 3.50ghz
Radeon R9 270x
8gb Ram 1866mhz