I'm an avid user of a nifty program called PersonalBrain. I like it enough that I purchased the PRO version. You can find out more about it here: http://thebrain.com

This afternoon, I opened up the main file I work with (called a Brain) and clicked one of the nodes with a note icon (see screenshot).

Click to see larger image

The note wasn't there. I clicked several other nodes with notes icons, with the same results. I tried unloading and loading the program; no luck.

I then explored the menu system and came across this under the File menu.

Utilities: Rebuild Database

I clicked it, waited for it to run its course (about 5-10 minutes) and tried again. All the notes were where they should be.

The moral of this story is that users of PersonalBrain should try rebuilding the database if they run into problems. It may provide the immediate fix you need.