The revision 172 of the HP3900 SVN repository adds support for the scanner HP ScanJet G2710, while the revision 174 include a little fix. Revisions greater than 174 are not compatible with sane 1.0.x as they are moving to sane 1.1.x. With the following patch to sane-backends, the HP ScanJet G2710 works well.
Created attachment 162105 [details, diff] patch to update sane-backends-1.0.19-r2 to include support for the HP ScanJet G2710
Just had a look at it - I would prefer not to depend on the availability of the svn repository, so a patch file which could be uploaded to the gentoo mirrors would be much nicer than downloading something with builds a patcher which patches the sources... Does not sound really difficult, but will need a little time (which is quite rare for me currently). Sorry, thanks for the hint to this project, but don't hold your breath.
Should be fixed in current stable
