My system forced me to reboot a couple of times with a message to press and hold the power button until the system powers down. My only recent updates are the 3.1 update and upgrading iStat Menus to the current release. Checking here to see if others are having a similar problem or it is a known fusion 3.1 problem. I'm checking at iStat too. I'll update with what I find. Thanks.
System: Model Name: MacBook Pro
Model Identifier: MacBookPro5,3
Processor Name: Intel Core 2 Duo
Processor Speed: 2.8 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 6 MB
Memory: 4 GB
Bus Speed: 1.07 GHz
Boot ROM Version: MBP53.00AC.B03
System: Model Name: MacBook Pro
Model Identifier: MacBookPro5,3
Processor Name: Intel Core 2 Duo
Processor Speed: 2.8 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 6 MB
Memory: 4 GB
Bus Speed: 1.07 GHz
Boot ROM Version: MBP53.00AC.B03