I am pulling my hair out trying to get Suspend/Resume to work. My setup:

Zotac ION - I verified that it is the latest rev that supports Suspend
4GB RAM
MCE USB dongle/remote combo
OCZ SSD
Minimal Jaunty
XBMC SVN 22528

When I press the Power button on the remote, the system correctly enters Suspend. When I press the Power button on the remote again, the system correctly Resumes. However, when I press the Power button on the remote again, it attempts to Suspend (the power LED goes off for a very brief moment) and then Resumes. DMESG is showing that it enters Suspend and then almost immediately Resumes. I don't see anything that is triggering the Resume. This exact behavior can be replicated even using the power button on the case so it is not USB or MCE remote dependent.

FYI - Suspend/Resume works 100% everytime in Windows 7. Does anyone have this working in Ubuntu?

i'm running my zotac ion diskless so suspend/resume doesn't work by default. Sorry I can't be of any help

OK, I have a little closure. Like I said, I installed Minimal Jaunty which is basically the base server installation and suspend/resume didn't work correctly. On a wild hair, I decided to install Jaunty Desktop and try it again. Guess what, it works 100% everytime. So now I know that there is something missing regarding suspend/resume in the Minimal installation. At this point, I am content to run Jaunty Desktop and have it go straight into XBMC.

Hope this helps others down the road.

My best guess would be that it was an issue with the kernel. In the future you can install server edition and then install the desktop kernel and use it. When I was using ubuntu I would run off the server kernel with the desktop edition.