Really hard to say - there are no "change logs" for the different versions. *Usually*, newer versions are better, but not always. Personally, I've settled on 2.4 (9.6.13.405512) as my "go to" version of 2.4. Haven't had any issues with it whatsoever and it also supports both Nuance and Loquendo TTS voices (I prefer Loquendo - they sound more "natural" to me).
Considering the build number, 9.6.13.405512 is newer than 9.6.13.319729. Is this (9.6.13.405512) the latest version for WIN CE? Do you have a download link for it?
Yes, as far as I know, 405512 is the latest version of Primo for WinCE.
Here is a link: [Please Register or Login to download file]
This archive contains two different executables, a CN (China) version and a WD (World) version - you want to use the WD version. I think the CN version is only used for Chinese maps or something like that....
You just need to put the SA maps into the "content/maps" folder (and put POI's into the "content/poi" folder.
Typically, when you download an iGO application, it just contains the bare minimum application without any maps, POIs, voices, etc. You need to download that stuff separately and install them into their correct locations.
The DEM folder is used for files that allow you to see elevation data in the maps. So if you don't have a .dem file for your region, you won't see hills and valleys on the 3D maps. Personally, I prefer using .dem files as it gives the 3D view a much nicer look. But they are not needed.