Isn't it more a matter of having a CF card that does do DMA and a
controller that does DMA, but a CF to IDE adapter that does not do DMA?
If it is really a case of a CF card that claims to do DMA but is
unstable if you try (I have found one model that does so), then it
should simply be added to the ide dma blacklist instead.
I blacklisted 'SMART CF' on my system since they have random read errors
and other i/o errors whenever DMA is enabled (while other cards work
fine with DMA enabled). They claim to do DMA, but sure don't seem to do
so reliably on this system. SiliconDrive CF works perfectly with DMA on
the same system.