Keyboard keeps disappearing

This is incredibly frustrating, but the virtual keyboard oftentimes doesn't appear when attempting to write an email or type in a web address. I've had to power off at least ten times and re-start to get the keyboard to appear. If I select the URL of whatever site happens to be open, the keyboard is supposed to then appear so I can type in an alternative address. Instead, the screen develops a grey mask with no keyboard present. I have to turn the **** thing off completely, it loses my history and then I have to start again.