I can't explain how exactly, but when I have the styled frames turned off sometimes throughout playing or after a loading screen, the addon reverts to using the styled frames. I want to say this happens when colored player class is disabled, it becomes enabled eventually.

I fixed this a couple days ago here 7868b3a and will have this on WoWInterface and Curse in around an hour. Wanted to test other changes before release.

The fix for this is now uploaded and awaiting approval on both sites.