MBP won't wake up with mouse or keyboard. Any suggestions?

I tried a few searches and nothing came up that addressed my specific problem so here we go:

I recently purchased a new HDTV that can finally handle the full resolution of my MBP. It works fine via a DVI-HDMI cable whenever the lid is open; however, the machine puts itself to sleep when I close the lid yet won't wake itself from this state when I activate either my mighty mouse or wireless keyboard. I have the "allow this device to wake the computer up" setting engaged in both the bluetooth and mouse/keyboard sections of preferences but still nothing. Has anyone else had this problem or know of a solution? I don't want to use Insomnia (or whatever the name of the program is that tricks the machine into staying awake when the lid is closed) as I am wanting to use the MBP to watch archived movies, surf the web, and play a few simple games through my new TV and over heating could become a real problem if the screen stays on too long.

Any tips or suggestions are greatly appreciated. Thanks in advance.

I don't know if this has anything to do with the "problem," but I don't have any wake up setting in the keyboard/mouse Preferences. I'm running Snow Leopard. Do you have third party (like Logitech) software running?

To run an external display with the lid closed on the Apple laptops, the laptop MUST be charging/plugged in.