Android maintains an operating system cache, just like a browser cache. And just like when a browser gets all wonky and then works after you clear cache, you want to try the same thing here. If you are not rooted, a factory data reset will do that for you. I do it for every major upgrade and highly recommend it - it works to kill weird bugs. Best to backup first, I recommend MyBackup Pro. I can show you literally hundreds of people on these forums who have thanked me for this advice, so, I won't make any guarantees other than to guarantee that it's worth a shot.