DMA in 7.3 only nodma for hda?

From my instalation with version 7.2 I know that from my 3 harddrives the hda does not like to have DMA put on. In 7.2 I could choose to not include hda. In 7.3 I heard that DMA is automatically put on. I can of course start with the failsafe possibility but would like to have DMA working on hdc and hdd (hdb is my cdrom). Could somebody instruct me how to proceed? Happy 2002