USB printer prints nothing

[Charles Trois]

I have a curious problem with cups.

Here is my setup:
15" LCD iMac
Epson SC 740 USB printer
YDL 3.0
Kernel 2.4.22, CONFIG_USB_PRINTER=y

The printer is found at boot at the right address, since the command

echo "print test" > /dev/usb/lp0

does indeed print "print test".

In order to get full printing capability, I followed
Dan Burcaw's howto, which goes like this:

1.    Point a web browser to: http://localhost:631

Done.

2.    Add a printer and start that printer via the web interface.

Clicked on "add printer" and went through the procedure. For "device",
chose "#1 USB printer". After that (printer added), clicked on "printers"
and saw that printer is "idle, accepting jobs, ready to print". However,
this line looks suspicious:

Device URI: usb://Unknown?serial=d420f000/

On the other hand, redhat-config-printer shows the correct address
/dev/usb/lp0.

There seems to be some sort of confusion between usp and serial.

3.    See if printing works ...

Of course not. An attempt to print (the test page or anything else) produces
no error message, but no output, and the job is listed as completed.

Any views on this problem will be welcome.

Charles