Ok. Just made my s2w 5300u working on 11.10.
Here is the instructions:
(do not forget to provide admin access if it's necessary with 'sudo')
1) Open terminal and check that system recognized scanner:
Bus 007 Device 046: ID 04a5:20fe Acer Peripherals Inc. (now BenQ Corp.) SW2 5300U
2) Check if SANE can see the scanner:
device `snapscan:libusb:007:045' is a Acer FlatbedScanner22 flatbed scanner
3) Now we have to download firmware for the scanner. Go download it from BenQ Service & Support site
4) Unpack 'Bin' folder from archive to, for example, your home directory.
5) Now check if folder '/usr/share/sane/firmware/' exists. If not -- create it:
6) Copy your firmware to '/usr/share/sane/firmware/':
cp -v '/home/user/Bin/u254v042.bin' '/usr/share/sane/firmware/'
Notice: unpacked folder 'Bin' may contents several file's and you have to choose one which suits you scanner. I did't know which one exactly and just tried a few of them. For s2w 5300u you need u254v042.bin If it'll necassery repeat steps 6, 7 with another firmwre files.
7) It's better to establish the right to read the file for other users because it is not known with what rights were packed file:
sudo chmod 754 /usr/share/sane/firmware/u254v042.bin
sudo chmod o+r /usr/share/sane/firmware/u254v042.bin
Notice: I did't do this step cause it was not so necessary for me.
8) Now we have to right path to file in config:
Find line 'firmware /usr/share/sane/firmware/' and comment it with '##':
Add after this line path to your firmware file:
Notice: you may not comment first line. It's also can be replaced 'your-firmwarefile.bin' with 'u254v042.bin'. I think you understand.
9) Replug your scanner. That's all.