Drivers on OS3.9 do work. I don't use any ohter software in both of my A1200s for CD.
Check what you have devs:dosdrivers, there should be CD0, open it with text editor and check what cd-rom filesystem and device driver it uses. Should be scsi.device and cachecdfs.
NOTE: You need to use rom update of OS3.9 to get scsi.device to work with CD-Roms