SonyDRX500UL burn+RW with Nero need Pinnacle for -RW Why?

[dvdinfo]

Whats missing ? can burn all + media DVD`s with the Sony using Nero recode 6.3 but have to use Pinnacle instant CD/DVD to burn the -RW`s Pinnacle will also burn the + DVD disc`s.
Copy to DVD, CloneDVD2, Xpress, will also only burn the +RW`s .
The Sony DRX500UL tried different firmware versions from f,g,h. with no differance.
The discs meduim used for + are +RW Sony & +RW Infinti. For the - are -R Discrite x2 & x4, -RW Infinti & -RW Packard Bell .