today i was on my blackberry 8310, and all of a sudden the connection goes from EDGE to GSM. this has never happened before, and i had this phone for about 2 months. the battery was at 75% in the status. i could not receive or send any messages, and could not go on the browser. my friends who also owned blackberries told me i should do a battery pull. i took out the battery for 1 minute and put it back in. it was still GSM. i tried to view the browser and it said that maybe my battery was too low. thinking that my battery is at 75%, i wanted to charge it to 100%. i connect the phone to the charger, and my phone says something about battery drained. the phone will shut down or something. so i jsut left it to charge. i come back 30 minutes later and the phone still does the same thing. what is wrong?