So I checked out the cooling fan on the Vantec case. It is immobile. With some compressed air I can 'kickstart' it, but it has basically seized up. The higher performance drivers either produced more heat or were less tolerate of overheating; without the fan they were cooked.
I need to do some more testing, including asking Vantec for a replacement fan, but my guess is that heat was indeed the culprit.
[Update 5/21: ... the Maxtor in the Vantec cartridge has been malfunctioning and now will not format. I wonder if the drive has been damaged! I've updated my table.]
If you think of standard ATA IDE drivers at all, you probably think they're pretty much an interchangeable commodity with some modest performance differences, some variations in rarely used diagnostic and configuration software, and unpredictable quality problems.
That's what I thought. I was wrong.
I tested 3 drives from three vendors (Seagate, Maxtor and Western Digital) in 4 different settings. All were fine in a routine IDE setup, but there were problems with a firewire enclosure and a removeable drive bay catridge.
|Maxtor Diamondmax||Seagate Barracuda||Western Digital WD 800|
|200 GB||200 GB||80 GB|
|PC MB IDE controller||Yes||Yes||Yes|
|PC Paradise IDE controller||Yes  ||Yes  ||Yes |
|OWC Firewire Drive w/ iBook||Partial ||Yes||not tested|
|Vantec EZ-Swap MRK 103F in PC||No ||No||Yes|
 Works as long as the iBook doesn't go to sleep.So, not all drives are the same -- by any means!
 This Paradise IDE controller emulates a SCSI drive. It supports 200 GB drives and works well with everything - except Retrospect 6.0. Retrospect, a notoriously difficult pile of software, has to be forced to use "NT Passthrough" when writing to a drive attached to this controller. This secret preference is enabled with the magic keystroke: Ctrl-Alt-PP. No, I'm not making this up. With the WD 80 GB drive Retrospect would stop after at some magic limit (I forget what it was), with the Maxtor it wouldn't even start -- but it would lock up my XP machine with an unkillable process that demanded a hard reset. With "NT Passthrough" enabled this problem goes away. This bug may be fixed in Retrospect 6.5, though I suspect others take its place.
The Maxtor worked initially in the Vantec PC cartridge, but then failed
Most surprising. The lessons I draw for now are:
1. Before purchasing an even slightly non-standard container for an ATA IDE drive check with the vendor what drives are known to work. If they say "all drives" then don't trust them. (SATA may be better).
2. Of the 3 vendors tested, only Wetern Digital MIGHT work in all configurations, but more testing is needed.
3. Not all bad behaviors come from one problem. In the course of managing this very aggravating situation I ran into three: the Seagate incompatiblity, a bent pin, and the Paradise/Retrospect incompatibility. And some people have to resort to television to explain increasing IQs!