TomTom 5/3 Garmin ique m5

I have a iQue m5 but do not really like the maps, i gave my wife my old pda (Mitac168) running TomTom 5 which i would like to run on the m5.
Problem i can not see which port to assign for the gps connection, the only way i can get it semi working is to configure the, other cable nmea gps, baud 4800, nmea on com2. The problem is it's intermittent, (TomTom 3 works fine)
i have also tried disabling all com ports by using gspgate & vspdce to see if the m5 own gps stoped working but no it still worked.
Any Help Please

After 7 months i have done it, if any other person need help please read on,
Go to Garmin down load update 2.60 and install, then load TTN5 , select other nmea gps
baud 4800, then com 4 (it used to be com 2) and away you go.