Sony Ericsson Xperia X10 :: Phone Draw Pad Failed And Google Account - System Update

right so the bottom buttons were working fine, but the next day, the back button takes me to the home screen :S so if im on facebook, press the back button, instead of going to the previous page. and i also set up the draw thing to unlock it, but as it was raining a little it said i entered it wrong too many times and asked for the google mail thing... but i really have no rememberence of making one, which is so ******* annyoying.

the only way ive found out to solve this problem is doin a phone software update, however as my bottom right button is working properly, everytime i hold it down to plug the phones usb, the phone just starts normally, so basically i cannot do the system update.