Epson 3200 + Firewire + Slides/Hangs on third slide ?!

It's an Epson Perfection 3200 Photo, connected via its FireWire
interface to a Mac G4 ("Gigabit Ethernet"), currently running OS X
10.3.2.

I am currently using the scanner to scan slides, four at a time, using
the slide guide, typically at 1600 dpi.

The problem I'm about to describe is remarkably uniform. Specifically,
the scanner stalls or hangs when scanning the _third slide_. When the
software in question is Hamrick's VueScan 7.6.69, the legend at the
bottom of the screen says "Autoexposing... 0% complete." This remain
there indefinitely it never proceeds to "Scanning." When it is Epson
Scan 1.21A (the software supplied with the unit), it displays the
"Scanning" progress bar which remains at 0% with the spinning pizza
spinning continuously.

I've seen this problem under OS 9.1 (though not tested extensively) as
well as OS X (10.3, 10.3.1, 10.3.2).

The problem never occurs when the USB interface is used (but, of course,
data transfer is significantly slower).

The problem is intermittent under FireWire. Scanning a set of four
slides completes normally perhaps 3/4 of the time, but the stall happens
very frequently.

I have already exchanged the scanner for another one of the same model.
Same behavior on both models.

I have experimented with the FireWire cabling. Originally the scanner
was daisy-chained through an external CD-RW. Now it is connected
directly to one of the ports. I've tried physically disconnecting the
CD-RW (so that the scanner is the only FireWire device connected to the
computer). Same results.

When the problem occurs, I can break the scanner out of the hang by
_opening the cover_ for a few seconds, then closing it again. At this
point, it acts as if it is proceeding normally. Sometimes I get a good
scan of the third and fourth slides. More often I will get a garbage
scan (using Epson Scan) or a file with, apparently no data (VueScan).

Anyone else using an Epson 3200 to scan sets of four slides via FireWire?

--
Daniel P. B. Smith, dpbsmith at world dot ess tee dee dot com
"Elinor Goulding Smith's Great Big Messy Book" is now back in print!
Sample chapter at http://world.std.com/~dpbsmith/messy.html
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