Laptop will not sleep!

My Dell inspiron 1526 will not enter into sleep mode unless I push the power button AND close the screen. If I do one OR the other the screen goes blank but it does not enter sleep mode because I can turn the screen back on quickly when I move the touchpad. I have checked my power options and those are all set correctly (it should sleep when I close the screen and it should sleep when I push the power button). I have searched google with no luck.

Any help on the issue would be greatly appreciated!

Thanks! Matt