I have the same problem.
On my Sharp Actius AL 27 laptop (my back up home computer that I don't use very often), the sleep mode
is greyed out and disabled. Seems to be one of two things because it used to work fine:
1- I accidentally uninstalled the display driver, and reinstalled it. That didn't seem to fix the problem, but I'm open for suggestions.
2- Also, I used to have XP, installed a new harddrive, and installed W7. I played with a few things during startup with XP, but W7 is different. I'm not sure about the BIOS thing, or ACPI suspend mode. I hit F2 upon startup and enter into setup, but my options are limited.
It's super anoying to shut down and reboot everytime I use this laptop! All I want to do is put it to sleep.
I would love some insight and sugestions!