Hi - just purchased a toshiba Tablet AT100 2 for my mum, but we're having a few problems. Initally the tablet was working fine, however after charging it the tablet would disconnet itself from wifi and would come up with the message "unable to obtain IP address", this stopped once I updated the tablet. Now when its being used the screen will go black and after a few seconds it will vibrate and return to the lock screen. When this happens we need to wait for it to turn itself back on, pushing the power button will not wake it up. Any suggestions or is the tablet faulty?