So I went ahead with the map upgrade and of course I ran into a big problem...
Downloaded the maps and burned it with imgburn. The first one was made with an ASUS DRW-B5ST - cross flashed to LITE-ON iHAS 124 C to allow me to set book-type to DVD-ROM - using the slowest write speed, 4x. With this DVD the installation ran almost to completion before starting over so the RNS appearently didn't like that one. Next attempt was made using a Samsung SH-W163A and imgburn @ 2.4x. After the installation had ran for about half an hour without any interaction from me the screen powered off - not unexpected - but when I turned it on moments later I saw that the unit had actually rebooted. After that it continued from where it was before the reboot - at about 50%. This time the installation completed and I got a message saying that the maps had been copied over to the HDD or something like that. Checked the version and sure enough it was now 8117.
The problem is that although the maps work fine I cannot use route navigation. After I have entered my destination address and click "Start" it shows the screen where I can select one of the suggested routes, but no routes are being calculated. If I put the DVD back in and reboot the unit I can hear that it uses the DVD for navigation instead of the HDD and now there is no problem with route navigation. I can even remove the DVD and it still works, but only until the unit has rebooted. There doesn't seem to be a problem with the DVD itself so my only guess is that something was corrupted during the installation, possibly because of the reboot.
I can think of a few things to try:
1. Is there any settings to force the RNS to reinstall the maps from the DVD? I suspect there is not, f*cking brilliant German engineering.
2. I haven't seen this suggested anywhere - and maybe there is a reason for that - but what about starting the installation of another map, such as the "East Europe V11 (8129)", and then abort the installation after it has ran for a few minutes. Will the RNS then be able to install "West Europe V11 (8117)" afterwards?
3. Josi from vwnavi has made a "RNS 510 Maps HDD Format CD" which will delete the current maps. However, I am on SW 6270 and I am not sure if the CD will work for this.