Ricoh MP5240A BIG DVD+R BURNING PROBLEMS

Hi,
my new Ricoh MP5240A is unable to write working Ricoh 4x DVD+R / Memorex DVD+R.

They are not working on my DVD+R compatible DVD-Players.
He can read Ricoh DVD+R / Memorex burned with PLextor 708 or Nec 1300(by friends). SO the Players do not need the DVD+R flag!

On a PC DVD-Rom the Ricoh 4x DVD+R / Memorex DVD+R (Ricoh MP5240A ) are working.

But when I am using cheap Primedisc DVD+RW an burn the same contents that was not working on the mentioned DVD+Rs the movie is running perfect.

So the question is what is the difference between DVD+R and DVD+RW burning with dvd-rom Videos??
Is the burner defective?

DMA is active
Nero 6.00.30 (newest) and 6.00.11(before update) was used
DVD-Rom Book Table did not matter if enabled or not