Navigator 5 help required

Hi, I have just revived my old ipaq 3850 to use for satnav use, I have installed navigator 5 on it, everything seems to work until It tries to load map, get screen saying no maps found, has this happened to anyone else or does anyone know how to fix, do i need to put maps in a certain file location so navigator can find them.
Used to have this on my acer n30 and it worked no problem.

OK, worked it out for myself, If anyone else is having problems like this, check your SD card. I was trying to use a 1gb to give me more space, only it was a high speed card, the ipaq obviously didnt like it, loaded TTN5 onto the original 512 card that came with Ipaq and it all works fine know.