There is a bug in the find bar that causes f-spot to crash if a very specific sequence of entries is made:

1. Create a tag named "abcd"
2. Open the find bar by typing "/"
3. Enter "ac" into the find bar
4. Move the cursor left by one character, so that it is between characters "a" and "c"
5. Type "b", this opens the completion box showing tag "abcd"
6. Press arrow down key to highlight the tag "abcd"
7. Press enter to select the tag -> f-spot crashes

I already know where and what the problem is. Since I'm currently working on the find bar I'll try to provide a fix within the next days.