MK IV won't accept 2011 High DVD

[amuse]

Hi, I upgraded my MKIV successfully to the official V.32 software. Now I seem to have a problem with the 2011 HIGH Version that I burned to a Dual Layer DVD (Verbatim DVD+R DL burned at x2.4 Speed). When I insert the DVD into the MKIV, the screen tells me that no CD/DVD was inserted and no navigation is working (TMC in red). When I pop back in the original 2004 Spain/Portugal BMW CD, it works (TMC goes to green) and navigation works (but with 2004 maps obviously ).
What could the problem be? Should I burn a single layer DVD? I read that this is possible by removing the other languages (except spanish).
Any tips?

Thank you!