Speed drop after playing game (Crysis3)

[viktorx]

Clean Windows 7 Home Premium SP1 with all basic programs and drivers installed (Catalyst 13.1), oclHashcat-plus v0.13, tried cracking and its working flawlessly (90k with --gpu-accel 16 --gpu-loops 128) without screen lag (with previous versions of oclHashcat-plus and 12.8 drivers and same parameters I had screen lag when cracking). Tried few dictionary files (computer worked 8 hours cracking but that's not relevant) and then I wanted to play Crysis 3 (and so I did). Finished playing (game fully closed, or system restart) and I wanted to continue cracking but now speed is 65k with same parameters (nothing changed). Tried restarting system, reinstaling drivers (uninstall, reboot, install again) and speed still the same, 65k. If I remove parameters and use default ones speed is just around 12k and before was 65k! Tried deleting oclHashcat-plus and unpacking it again and same thing. The only thing that works is system reinstall (witch I did - restore acronis image with clean install). My system configuration is:
AsRock Z77-PRO4, 8GB Kingston HyperX Beast 2400MHz, Intel Core i5-3570K and MSI R6950 Twin Frozr II/OC (unlocked to 6970 and overclocked to 840/1325MHz)...