Whether /usr/lib or /usr/lib64 get used depends on the distro. The packages
were compile for Debian/Ubuntu, which use /usr/lib.

The failure may come from not having /usr/lib in your default search path.

What does "ldd syncevolution" say?

What's the output of "/sbin/ldconfig -v -N" (run as normal user, there's no
need to actually modify anything with it)?