Ipaq fault

[Playbill]

I have an ipaq 3870 that is used only for sat nav with Tom Tom software. For some months on start up I got an error message box saying "Notification Error cannot execute Notifications\NamedEvents\EventWakeUpTomTom".
After tapping the "X" the message would go and everything worked OK. But now it takes many taps to remove the message. I now also find that when trying to enter information like postcodes where I tap on a letter, number or function, an adjacent letter number or function appears. I have done a hard reset that appeared to work for a short while but now has same faults appearing.
I bought it new about 3 or 4 years ago so is it worn out?
Any ideas about solving this problem or any where that repairs them at reasonable cost in southern part of UK. All computer repairers I ask say they do not deal with handhelds.