iPhone 4 battery indicator shows fully charged symbol and phone will not charge

I drained it completely (I wasn't using it much so it lasted from Friday morning to Sunday night), let it sit for an hour, and then plugged it into a known to be functioning wall charger. It recognized the charger with the signal noise, and showed the battery with just a sliver of red and a lightning bolt on the bottom. Nothing changed for an hour and a half, but then the charging signal noise sounded again, the phone turned on, and it began to charge (lightning bolt over batter indicator). When it reached 19%, the lightning bolt was replaced with the fully charged plug symbol, and when I woke up the indicator was still at 19%. I'll try it again once it drains, but I'm guessing I should go to the Apple store.

Honestly, here's the story: after about 6 days of being phoneless I went back to my dorm frustrated and thought about what could have happened inside the phone. I figured something came loose, and the only way for me to even have a chance of putting whatever was loose back was to squeeze the phone really hard between my palms. So I did just that and it worked! Might sound a little cuckoo and I'm not recommending it as a perfect solution, but hey, worth a try, right?

What a riot! I'm glad I could provide a temporary solution. :-)