Motorola V8 Keypad

Question

My new V8 was working fine but now seems to have developed a problem when texting. With predictive on or off, the keypad does not respond to the correct number of presses and is either ultra sensitive or not sensitive enough i.e just pressing the '4' key once skips the letter 'G' and jumps to 'I'. Similarly, the space key doesn't work unless you hammer it about six times?