Darn! (Or more forceful epithets!)
The problem came back.
I used RobW's Epson page. Filled out all the info in great detail. Here's the quite unsatisfactory answer I got back:
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Thank you for taking the time to contact Epson. It is my pleasure to
respond to your inquiry.
Unfortunately, you may or may not be able to get your product functioning
correctly in the Classic environment in OS 10.x. Difficulties arise due to
the Classic shell of OS 9 not being a true operating system, which causes
connectivity with hardware devices to become sporadic. If you need to print
with an OS 9 application, the best thing we can suggest to do would be to
restart your computer directly into OS 9.x if at all possible.
To restart your computer into OS 9.x from OS 10.x.
1. Click APPLE and go to SYSTEM PREFERENCES.
2. Click on the START UP DISK icon.
3. Click on MAC OS 9.x.x
4. Click on RESTART and then SAVE AND RESTART.
To restart your computer back into OS 10.x from OS 9.x:
1. Click on the APPLE ICON and then CONTROL PANELS and then START UP DISK.
2. Click on the MAC OS X icon.
3. Click on RESTART.
If you are not able to restart your computer into OS 9 from OS X, I would
suggest contacting Apple for further assistance regarding this.
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I will keep looking for an answer (sporadically, at least). It seems the only solution right now is a workaround: unplug the USB cable from the printer for a few seconds, then plug it back in again. If the printer doesn't show up, then select it in the Chooser.
Incidentally, from what I have seen in other places the same problem occurs with Panther X 3.x.
Bbob with a Cube