sane-backends 1.0.21 has been released on 2010-04-25. Since there are new backends (kodak, kvs1025, p5) it will require some additions to the ebuild. Reproducible: Always Steps to Reproduce:
In CVS, please give it a try.
Considering fixed, please re-open if you have problems.
I will give it a try tomorrow, but are you sure that SRC_URI="http://alioth.debian.org/frs/download.php/2318/${P}.tar.gz [...] is right? I think the right link is http://alioth.debian.org/frs/download.php/3258/${P}.tar.gz for 1.0.21. http://alioth.debian.org/frs/download.php/2318/ seems to be for 1.0.19.
Oopsie, thanks for the hint.