That sounds very similar to how I was set up when I used that drive.
I had the CDROM on IDE1 master, CDRW on IDE2 master, main HD on IDE3 master and backkup HD on IDE4 master.
If I remember correctly, I had my two (Western Digital) HDs jumpered to CS (Highpoint controller on board for IDE3/4)
and the Optical Drives (CDROM and CDRW) jumpered to master.
I do remember that I had DMA enabled.
-Sid
PS: you can also try using the device manager to uninstall the IDE controller. It will be re-detected and re-install on your next boot.
All these uninstalls and re-installs are only to help if a driver got ferked up somehow as can happen in Win98se. Basically, I always just
tried to make the OS think things were new and hoped the problem might "solve itself" with a do-over
All's fair when troubleshooing stuff like this. eg: swap which IDE controller does each optical drive, try putting them on a single controller
with master/slave reversed, etc. Sometimes just disconnecting the ribbons and reseating them can make a difference. If it does, replace the cable)
edit:
In days long gone by, there was a point in time where VIA chipsets had a difficult time with large file transfers when a soundblaster soundcard was used.
To solve this, I think only a motherboard flash to the latest BIOS is needed.
(It's easy even if you don't know how.... just post in here asking and you
will get more help than you can imagine

)