Next time you are getting random FC's and not in a specific program or app, just go into terminal emulator and run the fix permissions script. This worked when my phone was randomly turning off. This should be added to a rom so that it runs every night so that the phone is refreshed for the next day. It really does make a big difference.
1. Download Android Terminal Emulator
https://market.android.com/details?id=jackpal.androidterm&feature=order_history
2. Open terminal emulator, you will see a $ in the top left corner of the blue screen.
3. Next to that type su and hit the enter key on your keyboard
4. Terminal emulator will be given superuser permission after you hit "Accept" on the pop up.
5. Hit the menu soft key and choose the option to bring the keyboard back up.
6. You will now notice a # after the su.
7. Type fxpms next to the # and hit the enter key.
A bunch of scripts will scroll on the screen. It will take a while, (Took almost 6 minutes on my phone but will vary based on the number of apps) but when it's done you will see another # at the end and will give you an end time. Done. Back out of terminal emulator, give the phone a minute or two to settle and you should notice a difference.
I have selected to run the fix permissions option in CWM but it only takes a few seconds and doesn't seem to fix any problems. This method actually works and is definitely worth the extra steps.
Thanks to Landshark for providing this information in the Fascinate forum on Android Central.