the vorbis 1.0 library seems to have an additional parameter lenght in the function long ov_read_float(OggVorbis_File *vf,float ***pcm_channels,int length, int *bitstream) 1590 vorbisfile.c the arts-1.0.6 /var/tmp/portage/arts-1.0.6/work/arts-1.0.6/flow/gsl/gsldatahandle-vorbis.c has not I fixed it adding in the arts file that parameter set as G_MAXINT and is working
This has been fixed in kde cvs head. 3.1_alpha1 is very old and has been removed from portage (emerge rsync --clean). You can use the cvs ebuilds (www.gentoo.org/~danarmak/kde-cvs.html) or wait for 3.1_beta1 to get all kinds of fixes. I advise you not to use 3.1_alpha1, even if you get it to compile.