Perhaps the key to understanding how this might be possible is knowing that the Navigo V2 is simply a pocket PC with a GPS built in. It runs Windows CE.NET v5.
That's note QUITE true.
WinCE is a subset of PocketPC (known as Windows Mobile since 2005 or so).
Stuff designed to run on Windows Mobile or PocketPC will not necessarily run on a WinCE device, as WinCe does not have all the devices and libraries that are in Windows Mobile or PocketPC.
In particular the installation method for Windows Mobile is generally using ActiveSync which does not exist on WinCE devices. This means that you usually have to find another way of installing the software.
But I do understand that Memory Map will run on WinCE, and there are plenty of guides around showing you have to set it up.
dp