Hmm, mine first one appeared to have shat itself at one stage and then started working again before Amigakit even got a chance to reply to my email. This also happened with the other one I later installed in my towerised A1200.
They have both been working perfectly ever since and I've no idea at all why it happened in the first place
The symptoms that appeared with both interfaces were more or less identical, they simply didn't seem to be able to recognize the CF "hard drive" after a short while.
But, the odd thing is that when plugging a drive straight to the motherboard IDE interface it didn't seem to work either.
A couple of hard restarts & plugging everything back in as it should be worked & no problems since.
I think maybe I screwed up the jumper settings or tried two different HDDs on the primary channel, one master one slave...this doesn't work...well, it can, but takes a fair bit of dicking around software-wise.
Stupid question time, but they didn't seem to "die" around the very same time you installed IDEfix did they?
I found that letting it install stuff to the startup sequence and run IDEfix before the installation was actually completed basically rooted everything! Zetro warned me about this for the A600, but I also found the same issues with my A1200.
Maybe that helps, maybe not...hopefully something though...
PZ.