Well, according to that link, SANE only supports OSX up to 10.3.2. If true, it probably won't work under 10.5 and it's absolutely not going to work under SL. Smells somewhat hack-ish, too.
rotuts...Unless we know what model of scanner you have, we really can't help you. I suggest you 1) Ditch the SANE, and install a proper TWAIN plug-in.
Strix...Ditto. Get rid of SANE. Have you run Software Update to see if an up-to-date driver shows up for your LiDE 20? Unfortunately, I'm not seeing that model (nor my LiDE 600F) anywhere on
Apple's list of supported printers/scanners. That said, it may be possible that your LiDE 20 can use the Apple driver for the 100, 200, 700F series. It's worth a try.
Unfortunately, Apple's kind of screwed a lot of people with Snow Leopard with regards to perfectly good printers and scanners.