1.0.22 added network scan capability for SCX-4500W (slow atm compared to standard usb), but the feature disabled usb detection for this model, and maybe other Samsung devices :/ The commit fix is here: http://git.debian.org/?p=sane/sane-backends.git;a=commit;h=5ea227caeacd504b64eef301e83fa63e0a25b3f7 Diego, I have added you in CC in case you're planning a new commit for it, but I can add it in a -r1 if there is no objection
Patch added in 1.0.22-r1