Hi Giorgio, Sorry for the belated follow-up. I'm just about as puzzled as you but please find my thinking-out-loud comments in-lined below.
"Giorgio F. Signorini" <giorgio.signorini at unifi.it> writes: > Maybe I should point out here that the same scanner (with the same USB > cable!) works well on my laptop: Ubuntu 10.10, with > xsane: 0.997-2ubuntu3 > libsane: 1.0.21-2ubuntu2 That rules out any hardware problems with the scanner. > Problems arise only with my desktop: Ubuntu 11.10, with > xsane: 0.998-3ubuntu1 > libsane: 1.0.22-2ubuntu2 Could be caused by changed package versions or different computer hardware. > The same happens to other users > [see https://bugs.launchpad.net/simple-scan/+bug/888267] Hmm, keeping working Simple Scan and libsane packages from 11.04 and upgrading the rest of one's system to 11.10 breaks things ... Looks like something else is throwing a spanner in the (USB) works. > From what you say I suspect that the problem might be in the USB > management > > ** ubuntu 10.10 ** > libusb-0.1-4 -> 2:0.1.12-15ubuntu2 > libusbmuxd1 -> 1.0.4-1 > libusb-1.0-0 -> 2:1.0.8-2 > > ** Ubuntu 11.10 ** > libusb-0.1-4 -> 2:0.1.12-18 > libusbmuxd1 -> 1.0.7-1ubuntu0.11.10.1 > libusb-1.0-0 -> 2:1.0.8-4 > > Would it be useful/possible/advisable to downgrade these? Changing the libusb-* packages is unlikely to make a difference. Not quite sure how USB multiplexing might play a role here, but you could try turning off usbmuxd (if it's running) to see if that helps before downgrading. Another option is upgrading to 12.04. A truly long shot for the epkowa backend that came with iscan, and only really worth trying if the usblp kernel module is loaded (see `lsmod | grep usblp`), is to export SANEI_USB_KEEP_USBLP=1 before starting your SANE frontend of choice. Just make sure to use the epkowa backend as the epson2 (and deprecated epson) backends will not pay attention to this environment variable. Hope this helps, -- Olaf Meeuwissen, LPIC-2 FLOSS Engineer -- AVASYS CORPORATION FSF Associate Member #1962 Help support software freedom http://www.fsf.org/jf?referrer=1962
