i've had that happen before.
sometimes just from stress, or maybe it is a strange bug or something.
i hope you're not coming down with anything!
just get some rest, go to bed early.
and take your vitamin C
hopefully you'll feel better soon.
I think it might be stress. I've been under a ton of it lately. I got some hypnosis CD's on ebay that I think will help me get through this. Now I just have to get them!