Drat, I didn't think to remove the old drivers, I'll try that too.
Edit: I found this on the same website:
Outdated or incompatible device drivers
If the computer is running outdated device driver files, they may not support power management and they may cause incompatibility problems. This behavior prevents a computer from entering or resuming from hibernation and standby. Drivers are the primary causes of hibernation and standby issues.
Make sure that you install the latest updates for the operating system to all the devices, especially audio devices and video devices. If you are not sure which driver is causing the issue, go to the "If you have outdated driver files, run the Crash Analysis tool" section.
So yeah the drivers could be outdated and I will remove the old mouse drivers from my G5.