Printer woes (Epson Stylus Color 440)

[eliddell]

First, a little background: this is a small parallel-port color inkjet printer, about ten years old now.
It works perfectly when connected to an old machine running Windows 98 and the manufacturer's drivers. I was hoping to switch it over to my Linux box, and was happy to see that gimp-print/gutenprint claimed to support the printer. Installation *appears* to work, with no errors showing in the CUPS error log.

However.

Simply put, no matter what I try to print, what the printer actually produces is a couple of characters of gibberish followed by a form feed (and repeat ad nauseum until I kill the process doing the printing the hard way). It seems particularly fond of a-umlaut. It reacts this way regardless of whether I use the gutenprint drivers intended for this specific printer, or the foomatic ones, or, for that matter, the generic Epson inkjet drivers. It also reacts the same way to attempts to send status requests through escputil, although the CUPS web interface seems to be correctly detecting its state. Attempts to send plain text directly to /dev/lp0 result in the printer's status light flashing as though it's trying to do something, but no output is ever produced. And nothing of interest that I can detect ever shows in the CUPS error log even when the log-level is set to "debug".

However. (Yup, another one.) If I share the printer from the Win98 computer and set my Gentoo box to print to it over the network via samba, Everything Works (well, there are a few artefacts in the test page printout, but I can live with them). Using the exact same drivers.

I am utterly mystified as to what's going on here. Does anyone have any ideas? (Please save me from having to boot that old Windows machine every time I want to print . . .)

media-gfx/gimp-print is version 5.1.4
net-print/cups is version 1.2.12-r4
net-print/foomatic-db is version 20060720
net-print/foomatic-db-engine is version 3.0.20060720
net-print/foomatic-db-ppds is version 20060720
net-print/foomatic-filters is version 3.0.20060720
net-print/foomatic-filters-ppds is version 20070501

Parallel port support is compiled into the kernel.
dmesg shows that the parallel port is recognized and correctly identified as "PC-style". Unfortunately, the printer was not attached when the system was last rebooted.

My system: