16H5s on JMicron 363

I have a gigabyte DS4 which has one IDE channel provided by a JMicron 363. Gigabyte doesn’t say it’s a JMicron and even labels the chip as Gigabyte, but it’s actually a JMB363.
I have a Liteon 16H5S set as master, and a NEC 3500 set as slave. I’m using the latest (beta) drivers from JMicron v1.17.04.00, but the results are the same even if I uninstall the JMicron drivers and use the IDE controller with the default Windows driver.

Both drives work fine at reading disks. The liteon does error scanning just fine. But when I try to write (Nero 6.6.1.4) only the NEC works. The liteon gives an error “DMA-driver error, CRC error”.
As both drives are recognized as SCSI with the JMicron driver there is no DMA option to check. When I uninstall the driver and use the default windows driver the drives are recognized as IDE and then DMA is enabled on both drives, but the Liteon still can’t write.

I’ve read about other people having trouble with the JMicron crap, but most report that their problems were solved with the beta JMicron driver.
It goes without saying that I’m using all the latest firmwares and drivers for everything. I also tried to use the driver that gigabyte gives for the JMicorn controller, but it’s even worse than the beta driver I’m using now.