Please describe the problem:
I have a group of similar categories, "Race: Feline", "Race: Humanoid", "Race:
Lupine/Canid", and so on.  Searching for images in one category turned up images
in all the similar categories.  I had to hand-edit the category file and
comments files on 300 images to get rid of the colons and spaces, after which
the search function seemed to work fine.

Steps to reproduce:
1. Create categories "R: One", "R: Two", and "R: Three".
2. Assign several (I did six) pictures each exclusively to one category each.
   (No picture should be assigned to two categories)
3. Search the current directory for images under one of the above categories
("R: One")
4. Click on "View" to see the results.
5. You will see all of the pictures assigned to "R: One", "R: Two", and "R: Three"


Actual results:
I assigned 6 pictures each to "R: One" and "R: Two", and three to "R: Three". 
After searching for pictures in the category "R: One", I got all 15 pictures.

Expected results:
I expected to get only the three pictures I had assigned to the category "R: One"

Does this happen every time?
Yes.

Other information:
Parenthesis and spaces do not seem to cause the same problem, but I have not
checked thoroughly and I suspect they may.