MacBook Pro :: Mavericks Will Not Sleep

ever since a few weeks ago, my mbp mid-2009 15" running mavericks will not go to sleep. when i use the apple menu or when i shut the lid, it will take awhile and then goes to sleep, but immediately wakes up again. i can tell by the indicator light and by the sound of the machine. It's not a user issue, as it happens on all users and even on a guest user. it happens on the user's login screen. i repaired permissions. no problems with the hard drive test. i turned off all sharing. i quit all apps. i did a smc reset.

I have an SSD installed as my main hard drive. I mounted another SATA drive in my optical bay. I even unmounted that drive thinking it might be that (although it was working fine for years before).On activity monitor, i notice kernel_task is running, but not high; however, i notice that the idle wake ups is very high - over 1000.