I had the same issue where the pda stop responding and i had to reset it. BUT, as a hint, there was one day when it worked. use google map application to start the gps on a port from 1-4 and then close the google application and open igo and it will work. but, in order to start google map you need internet connectivity which costs you if you are outside the country
another solution is: sell imate and buy a normal phone and a gps separately
in the end this is what i've done because the battery on imate is very very poor. less than a day if you use it to make calls.