You either installed 12.04.3 from scratch or opted into upgrading to the backported raring kernel. https://launchpad.net/ubuntu/+source/linux- lts-raring indeed exists, so if you are running that kernel then apport is correct in filing bug reports against that instead of "linux".
** Changed in: apport (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1218183 Title: Using "apport-bug linux" cannot report a bug against the Linux kernel To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1218183/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs