iPhoto "Straighten" Glitch

This has been driving me berserk!

Although I am a new member, I have been using Macs and Apple products my whole life. I would describe myself as extremely adept at using computers.

I recently updated to iPhoto 9.2.1. I am just a hobbyist photographer, and iPhoto is my program of choice for managing photos. I use the "enhance", "retouch", and "straighten" features to edit my photos because they are easy to use and fulfill my needs. They work great. After updating to 9.2.1, however, I have found the "straighten" feature almost unusable. After I straighten a photo a few degrees, iPhoto doesn't keep my exact settings—eg: I straighten it 1.5º and it immediatley snaps to 1.2º or 1.8º. It seems to favor those two numbers. I try 0.6º, and it goes to 0.3º. It is a problem with all the numbers—23.7º goes to 23.2º.

Any ideas?

I am convinced this is a bug.

Thanks.