wont start unless plugged in

[RideAWalrus]

I have an unrooted droid x that works perfectly fine when on, the battery lasts its normal time as well, but once turned off it will not start again unless I plug it in to an AC charger, car charger wont do it. Even when i plug it in it sometimes wont work, i have to pull the battery a few times while plugged in then it boots up. It just started a few days ago, no idea why.
Any help?