The real problem is the CF card itself; as you can see, the CF card does not support jumpering Master/Slave, and the Adapter does it instead. Now imagine some cards don't respect it and set to single drive mode and take over the entire IDE bus. I have had such an issue using Hitachi's 4GB Microdrive (form iPod mini) with A1200. I could not hook up any other drive - no matter if they were CD-ROM or HDD's - as a second device together with the Microdrive. And I could not set the Microdrive to Slave mode. The only solutions were to:
- use Microdrive alone (a poor solution, actually)
- use another disk (personally, I exchanged the Microdrive to a 20GB 2.5" HDD)