One issue that I see here is that libnss3 is making trouble in the apt.log. We have a old version in dapper with a epoch so that may cause problems.
$ rmadison libnss3
libnss3 | 3.12.9+ckbi-1.82-0ubuntu1 | natty | amd64, i386
libnss3 | 2:1.firefox1.5.dfsg+1.5.0.3-0ubuntu3 | dapper | amd64, i386, powerpc
One issue that I see here is that libnss3 is making trouble in the apt.log. We have a old version in dapper with a epoch so that may cause problems. ckbi-1. 82-0ubuntu1 | natty | amd64, i386 5.dfsg+ 1.5.0.3- 0ubuntu3 | dapper | amd64, i386, powerpc
$ rmadison libnss3
libnss3 | 3.12.9+
libnss3 | 2:1.firefox1.