I tested svxlink on my stable amd64 system. 'svxlink' and 'qtel' both crashed shortly after start with a segfault. Problem is due to a compilerflag (-fpcc-struct-return) and fixed in new version (see http://www.nabble.com/SvxLink-64-bit-issues-resolved-td22260875.html). For new ebuild for svxlink-090426 see bug # 279699 (please add ~amd64 keyword). New versions works well under x86 and amd64.
So, basically, this is a request for a new version. *** This bug has been marked as a duplicate of bug 279699 ***