Hello everyone!
I'm not sure whether this place is the right to ask this question, so if it's not, just please move it to the appropiate sub. Thanks!

My problem in short:

Whenever I use the standby mode on my computer (or more likely, it goes into standby automatically for idling too long) I cannot turn my computer off.
So basically, after standby, my PC recovers pretty quick and I can use it with no problems at all for however long I desire. But then the next time I'll try to turn it off, the system seems to shut down, windows quits and everything else, but after the log-off screen the CPU and/or the cooling does not seem to get turned off. They will continue running as long as I don't unplug the PC or turn off the power source on the back of it.
What could cause this?
Here my hardware stats:
Win7 Ultimate 32bit
ASUS P5K motherboard
Intel C2D E6850 @3GHz
Gigabyte HD 5450 1GB DDR3
Aeneox 2x2GB DDR2 RAM

Thanks for your help in advance!

Maybe a hardware issue. I honestly don't know, but if your computer is relatively new you could contact the people you bought it from. This question might be better suited in the computer section, or try googling this.