I went through the same headache with my Samsung ML-2510. The problem seems to come from the "USB Autosuspend" feature that was introduced in the 2.6.20 kernel. It's supposed to power down USB devices when not in use, but many devices (especially printers and scanners) don't play nicely and refuse to power on again. Read more about it: https://lists.linux-foundation.org/pipermail/bugme-new/2007-June/016443.htmlhttps://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.22/+bug/128058https://bugs.launchpad.net/debian/+source/linux-source-2.6.20/+bug/85488
I'm not sure there has been any progress on this little problem yet. There are supposed to be workarounds that do not involve recompiling the kernel but I never got any of them to work. In fact, I decided to use another linux box of mine as a CUPS print server instead, since it was already running on the 2.6.17 kernel. If you really want to use this printer on an updated kernel, then I believe the best way is to recompile the kernel *without* the USB auto suspend feature. You can find it in the genkernel menuconfig although I am not exactly sure where it is. Look under "peripherals" or "usb" or something along those lines. I do remember that it was marked "EXPERIMENTAL" so it's beyond me why they would enable it by default. Just disable that and recompile and then your printer should start responding when you tell it to print (provided you configured CUPS correctly).
Someone more knowledgeable than me might have a better suggestion. Good luck.
EDIT: OK I might be mistaken. This thread on kerneltrap.org suggests that autosuspend might not be the culprit since they changed the way suspend works in 2.6.23. Here is the thread: http://kerneltrap.org/mailarchive/linux ... /13/259148
Which kernel are you running anyway? The command "echo $(uname -r)" will tell you. If you are not running 2.6.23, then simply upgrading to it might fix your problem.