Motorola Droid :: Shutdown - Unlock / Turn On?

I was working on a paper on my computer, and my Droid was on my desk charging. My girlfriend sent me a message on the computer saying she will be over shortly, and I told her to call me in case I don't hear her knock. So a long time went by, and I was like "wow, she has to be here by now" and checked my phone to make sure I didn't miss her call. I hit the unlock button and nothing happened. I held the unlock button to turn the phone on, nothing happened. I had to physically remove the battery, then pop it back in and it worked magically. At the time, I thought that it was just a fluke.

I was writing messages, e-mails, browsing, etc., before class and I put my phone in my pocket right before I walked to class. When I got out of class, I tried to unlock my phone, and AGAIN the phone would not unlock/turn on. This time however, I made sure this wasn't a battery issue. I made sure all the pins on the phone were making contact with the battery and it would still not turn on. I had to pull the battery out, and put it back in, and it worked immediately. (I am literally pulling the battery out and popping it back in immediately, no wait time in between). I have seen a few threads about apps freezing, force quits, random restarts, and I have none of that (I have never had an app force close). I am just wondering if anyone has had a similar issue? I don't even know where to begin debugging, since I haven't really installed anything in the last week.