PC won't sleep on timer

[strumpusplunket]

System is as in sig, and having a minor issue with the PC going to sleep.

If I select sleep in the power options in start menu it goes to sleep just like it's supposed to, but I've set it to sleep after one hour idle in power options but this does nothing. The display powers off after the time I set, but it won't go to sleep this way.

I've stopped all the scheduled tasks with repeated actions that I can see, and not sure what else might be causing this.

Any ideas what else I might try?

 

[Bego2K]

Have you checked the power options in the BIOS? Not sure if a program would prevent the machine from going to sleep but worth a look. See what programs you have running in the background.