See the small black spots? They show up small here but it's obvious in the first one, and you can see it on the thumb of the second logo.
I did consider the alpha problem, but I did redo them a few times and the other types of logos work just fine, that's why I'm not sure what's wrong. Maybe the file type is wrong? They're all BMPs, should they be JPGs or GIFs?
Thanks for the quick responses!