Try CoPilot Live 6, it states to have "Support for Windows Mobile 5" which is a dam site more than TTN5.
This is the latest response from TomTom regarding WM5
"Windows Mobile 5 devices have not yet been tested so at this time we are unable to comment on its compatibility.
Should this occur and PDAs are found to be compatible they will be added to the compatibilty listings on our website
At present we do not have any time-scale for testing
With best regards,
The TomTom Customer Support Team"
Being a current TTN5 I don't know much about CoPilot other than from comments on
http://www.pocketgps.co.uk. Would be interested in any comments you have if you buy CoPilot as I to need a reliable working GPS system (+35k miles a year all over UK)and want to upgrade my X50V to WM5 ASAP.