@catymag, Here is what i done for my 3790 with the melbourne sensis map. as navteq file has bothe sinsis.img and navteq.3d files so did not try with that file.
1.jetmouse 1.5 latest. add my gps 10 dig number.
2.select mapset..add 800 in FID pressed ok
3.click generate on map unlock code. copied that code.
4. opened notepad..added the code in top line only.
next what i done is what i called vage as it is not explained in detail, but gave it many trys.
( before that i change the melbourne map to gmapsupp.img although its not needed on the 3790 the map is seen on my gps,but followed you instructions)
5. on notepad after entered the map unlock code top line, i selected "file", select select "save as" changed file name from *.text to gmapsupp.unl , in save as type i selected "all files" , in encoding left unchanged (ansi), final clicked save.
6. file is on desktop. closed the notepad window.
7. now i have both img and unl files done to best understanding.
8. on my SD card i made a folder called "garmin" as it is mentioned in posts ( note i also have folder called "maps" this is where all my other maps are sitting including xplorer NY and Paris and many other maps etc)
9. I cut and paste (not copied just to make sure) both img (unchanged) and unl (created) files to "garmin" folder on sd card.
10. Placed into 3790 and reboot the gps, in map directory all maps i have are shown, including the melbourne cityxplorer in full title as posted here. Maps running (ticked) are melb xplorer , Au-Nz-dem , CN AuNz 3d and traffic trends Cn AuNz.
11. Returned back to main window changed car to pedestrian.
* with explorer there are to be extra information as in "transport" the normal garmin map have left out ALL "commuter railway stations" garmin says cityxplorer will have all that. OK...there is NO extra information or any difference in POI this tells me, something is wrong.
Note; I have used "Pedestrian mode" with what i done above and without xplorer and the function is exactly same.
So this is what im having issues with.... I just dont get it, i would like to know if ANYONE has achieved the end relsult and can tell me if it works, also catymag thanks for your help, if i have missed something please let me know as i have done what i understand within this forum.
Cheers