Bug #904853 is related: for a i386 package installed with –force-architecture on an amd64 system, the Synaptic symptom is the same (”The list of installed files is only available for installed packages” ). The info files in /var/lib/dpkg/info don’t have a :i386 in the filename, as (I’m guessing) Synaptic figures for an :i386 package they should.

jani@saegusa:tmp$ ls /var/lib/dpkg/info/lightscribe*
/var/lib/dpkg/info/lightscribe.conffiles /var/lib/dpkg/info/lightscribe.list /var/lib/dpkg/info/lightscribe.postinst