the foolowing error is something you get when you have multi builds of the same rpm
ie kernel-2.6.5 and 2.6.7 etc.
there is two ways to solve this problem
1. if you have synpatic run it and remove extra kernel and gpg-pubkey rpm the will remove the error

or
2 this is a much better option because you may need extra builds as something to fall back to if something goes wrong
as root or with root priv run :vi /etc/apt/apt.conf
and add
RPM::Allow-Duplicated { "^gpg-pubkey$"; };
RPM::Allow-Duplicated { "^kernel$"; };
to the bottom save and then run apt again
hope this helps