Mac OS Lion will not wake up

I upgraded from Snow Leopard about a month ago. I leave the laptop running instead of turning off every night so I can pickup where I left off. However, when I open the cover it does not wake up!

I tried tapping on every key, tapping and double tapping on the track pad but no dice. I hear the hard drive spinning and the keyboard glows but that's it.

I see some other posts on this but it is frustrating that I will have to reboot every day now.

I just shut the cover, waited, then re-opened it and now the keyboard does not glow, the LED does not glow, hard drive still spinning - no response. I had to power down. It's powered up again now and all of the windows restore which is good but having to reboot is a real pain.

I need to get work done.