I have my mkIV with v32 and night mode (self modded) the unit is manufactured 2008 and so far all copies from original dvds or from downloaded images are working good. I worked so far with high 2009; 2009 - update 2 (am I correct or was it another version?) and the last 2010 update. I added my own POIs and still ok.
I use verbatim DVD, burn with ImgBurn, at the beginning I did at the slowest speed but it took so long time, so I now burn at 2/4 speed and it works good (touching wood).
I believe it could be a firmware issue related to the unit or a little bit older lens.

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I could show my BMW but I prefer to show my wife boobs...but, sorry, only by pic.