Vista ultimate x64 sleep problem

If I select "sleep" from the start menu, when I come back to try and get back into my computer I cannot. The fans will come on, things will seem to be starting up, but nothing past that. It sounds kind of like it is trying to turn on, failing, almost turning off, then trying again. Meanwhile the whole time Windows seems to be attempting to access both my optical drives, whose activity lights are on.

I have found that if I turn the computer off at the power supply, leave it off for a few seconds, and turn it back on, the computer will then, apparently, boot up--but it is not a clean boot, it actually ends up returning me to my desktop as it was before I put the computer to sleep. I am glad that I can at least get back to the computer, but it's a little inconvenient and time consuming, and I'd much prefer to just be able to return to my desktop with a mouse-click.

Is there a known bug with sleep or does anyone have any ideas as to what might be causing this problem on my system?

Thanks in advance.

Here's a good tutorial on troubleshooting Sleep problems in Vista:

http://www.vistax64.com/tutorials/ [...] blems.html