Thank you for noting your solution. I went ahead and cleared out data on several apps including FB to no avail. Read your post and tried Calendar, still no fix. I started going through my list just as you recommended and found "Internet" to have a large difference between App size and Data, for me .91 MB in App size and something like 20MB for Data. I cleared it out and phone sprung to life. Yeah!
Phone info: Droid Incredible 2.3.4