I'm not entirely sure what the rules are about double posting here, but I decided to make a new post in case you have already read my previous post and decided not to respond.
I did some searching around the internet for other cases of my problem (I had found a few before I created this thread, but none of them had a solution), and I came across this thread:
http://forums.battle.net/thread.html?topicId=18031081226&postId=182744233354&sid=3000#0
(Sadly I didn't find that thread before I found the solution myself. Would have saved me a lot of time.)
Apparently others have found that changing their resolution seems to fix the problem too. I'm not sure exactly why the resolution is an issue or who is capable of fixing the problem. (Though, it seems to me like it's something Blizzard could patch.) I would suggest that you at least add it to a list of possible problems and solutions etc., and suggest it to anyone you may come across that has a similar issue.