See Summary, besides the configure script checks for libpng, so I think that should be added to RDEPEND
Created attachment 109633 [details] eboard-1.0.3.ebuild.patch
I was able to compile and install eboard-1.0.3 successfully as well with --nodeps - ignoring the imlib-1.9.15-r1 depend. The system in question is free of both imlib and imlib2, and eboard works fine.
thanks