Xperia X10 :: Screen In It Doesn't Lock Anymore And Camera And Ringtone Don't Work

1) the screen doesn't lock anymore; i mean the slide to unlock thing doesn't appear : when i lock the phone the screen just goes black but when it's in my pocket it unlocks itself and start messing around like calling by itself!

2)the central button now only lights the screen; it doesn't go back to the main screen anymore! i have to use the button <-- (back) as many times as i entered in a folder to go back to the main screen..

3)the phone doesn't ring anymore! i can listen to music or whatever but it will just vibrate when someone calls me! also when I try to change the sound level with the side buttons, even if i go max, it will say :Ringer Volume silent ringtone selected

4)the camera crashes as soon as i open it, it's just black as if something was blokcing the camera.. the only option reamaing is to turn off the phone and then reboot!

5)by the way when I press the shut off button usually you have 3 choices : *plane mode *power off *xxxx (i just can't rember what it was)well now i only have one option: power off!

6)Oh btw it has already happened to me a few days ago; after much searching in the internet with no answers i simply did the 'factory data reset' thing and it worked!