What to check for Samsung ML-1865W

[Paolo Proni]

Hello, I have a laser b/w ML-1865W and it works if I use a base Debian 5 32bit with cups, installed by apt-get.

If I try that printer on another machine, which has a Vortex processor, CUPS does not see the printer, but it can see an old HP model.

If I write lsusb I can find the printer, so I do not understand why nor CUPS, nor the Samsung utility can see the printer.

Here am I asking what I should check in order to know what I should install or change. I do not know what to do.
lsusb shows me that the printer is connected, lsusb -v shows me that the class is  printer, but cups cannot see it as a printer.

My question is: what does CUPS look for, in order to find the USB connected printers? What should I check ?

Thank you