Thanks for your help.
The drive was recognized as IDE in my old PC, so it should not be the firmware. I rather not change a running drive, since it gives me great results with verbatim and the current FW.
Regarding the driver: I installed the MoBo drivers, but I'll look for a newer JMicron version.
Unfortunately IMGBurn freezes so hard that I could not see a log
Nero runs fine, strange!