Hi,
i've downgraded to Josis 3810_noru (because the normal 3810 doesn't work on my c4a-devices). After updating the map i update the firmware again to 5230. All works fine. Now i've tested the following situation. All DVD/CD-Types will read perfect, only MAP-DVD has this issues. At least i burned the v9 WE with Nero Burning ROM v11 as Image with 4x speed on Verbatim DVD+R DL. The advantage of Nero in this case is the automatically setting of Booksize to DVD-ROM. And what should i say? There are absolutely no problems to install the map in this f*ucking device without downgrading the firmware

Another test with burned v9 on Verbatim with IMGBURN doesn't work, means there are errors on DVD. This DVD works in another RNS510 like a charm, without showing any problems. This is the only thing i can say as solution for this problem, i think the problemes come from combination of DVD, Burner and Burning Software.