I'm new to the world of mobile sat nav so can't offer much help.
Did you copy the great-britain-map folder to the root of your memory card?
It should have loads of files inside it, i.e. cline.dat, cname.dat, cnode.dat, etc. There might be speed camera files there too, i.e. pocketgps_uk_***. It will probably be over 100Mb.
Some folk of said that you need an activation code but not sure about that either lol.