So I've had this phone (Samsung Galaxy 551) since last December. I loved it until about the beginning of this month (May) when it started acting funny. The lock button doesn't work and if it does lock it shuts the phone off. The home button, as well as the lock button, initiates the menu with airplane mode, power off, and silent mode. I fixed it once by taking out the SIM card but I've tried it again and it hasn't worked. I also tried taking out the SD Card to no avail Sometimes when I'm using the keyboard, the function and shift button either lock the phone, shut it off, or bring up the menu with airplane mode, power off, and silent mode. The only way to lock my phone is to set the auto lock to 15 seconds and wait for it to lock. To unlock it I have to slide out the keyboard. As far as I know the software is completely updated and there's no water damage. I've been searching since the beginning of May for a solution so if any of you know how to fix this it'd be much appreciated! Also my service provider is Bell if that helps.