One possibility - did you try to install ia32-libs before an initial run of update manager (and thus an update of the package cache)?
-- Ia32libs Package error on X64 systems https://bugs.launchpad.net/bugs/578791 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
