When I tried to emerge evolution on my system with only kde and no gnome, the helpfiles in evoultion failed at make install because scrollkeeper was not installed. I emerged scrollkeeper and then went to /var/tmp/portage/evolution-1.4.0/work/evolution-1.4.0 and typed make install. This time it worked. gtk2 and gnome in USE flags.
thanks for your report. i've added app-text/scrollkeeper back to the DEPENDs. i guess i removed it during the dev stages when they didn't have any docs ..