I too have a 9300 and get the same message. The problem I have found is that there are different versions of tt5. the one that works on the 6600, 7610 (normal screen) etc. is for series 60 platform and the one for 9300 and 9500 (wide screen) is a series 80. there is a good site reviewing the two types and I have put a link below. According to the official tomtom site the series 80 is due soon. (go onto the site and try to buy... you will see what I mean). Hope that helps. I'm new to this, so if I'm wrong anyone please feel free to put me straight.
http://www.allaboutseries80.com/revi...ew2.php?id=143
PS Does anyone have any ideas about the 7710... I can't get it to work on that either.