In reply to:

---

I thought that those compact flash readers required driver software support. I didn't think you could just plug one in.

---

That's the beauty of compact flash. It has three different interface types. One of them is called True IDE mode where the device emulates a standard IDE interface when certain pins are wired correctly. You can plug them straight into a PC if you want to. What you will need drivers for though is hot plugging/unplugging but this will also require buffer hardware which these cheapo adapters do not have.

Anyways this sounds very much like the problem where some drives don't like co-operating with each other.