package mythexport 2.1.5-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Marvin Lee Rice]

everytime I try to update my system i get the same thing

i get this message
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used.GPG error: http://deb.opera.com stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E585066A30C18A2B

W: Failed to fetch http://deb.opera.com/opera/dists/stable/Release

W: Some index files failed to download, they have been ignored, or old ones used instead.

ProblemType: Package
DistroRelease: Ubuntu 10.04
Package: mythexport 2.1.5-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-46.108-generic 2.6.32.60+drm33.26
Uname: Linux 2.6.32-46-generic x86_64
Architecture: amd64
Date: Mon Jul 15 23:46:50 2013
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationMedia: Ubuntu 10.04.2 LTS "Lucid Lynx" - Release amd64 (20110211.1)
SourcePackage: mythexport
Title: package mythexport 2.1.5-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[dino99 (9d9)]

This version has expired a while ago