To make aMule 1.2.5 compile and work on FreeBSD just copy the attached file to your aMule 1.2.5 directory, change into the directory and apply the patch (patch < aMule-1.2.5-freebsd-patch.txt). After that you can start the installation procedure (configure, gmake (!),...).
cd aMule-1.2.5
patch < aMule-1.2.5-freebsd-patch.txt
Thank and credits for this go to Kry!