Unresponsive Caps Lock Key

First off, I don't know if this is a hardware or software issue, so sorry if this is the wrong forum.
Just yesterday, my MBP (that I got in June) just decided it doesn't like its own caps lock key. The little green light comes on, but it does not produced capital characters. The shift key (and shift lock), however, do still work just fine. And, quite intriguingly to me, if I have the caps lock key activated, the shift keys can no longer produce capitals. Is this a problem anyone else has been having or any ideas of how to remedy it? I do have full service Apple Care, but I'd prefer to not have to go through that. Thanks.

I figured it out. I had downloaded the IPA keyboard configuration for a language class I'm taking. Apparently, the IPA keyboard was causing those problems. What I still can't figure out, though, is why it was randomly switching back and forth between standard US and IPA keyboards without me going into settings. I thought it might be based on which application was active, but that wasn't the case. I have since disabled the IPA configuration and so alleviated my problems, but it would be nice to be able to quickly switch back and forth without worrying about these things. Oh well.