I am using the 30 day trial with the sample UK data TeleAtlas data and having a problem getting the correct town.
When I reverse geocode with latitude 51.66041 and longitude -0.89834, the only town returned is Wycombe. The location is actually Stokenchurch. I have set a breakpoint and examined the address object, Stokenchurch is not found in any of the strings or string arrays.
This information comes from the data provider so I will send them feedback with your note. Each provider is constantly making updates and they do rely on customer feedback for fine tuning the information. In the meantime, it might be worth testing with the Navteq sample data for the UK to see if it matches towns better for you.