Error message received when trying to update the software on this PC.

[beerbunny]

For about a week now, I've been getting the following message when trying to update the software;

E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.

I've got no idea what to do about it. I've tried updating using 'apt-get' in a terminal, but I get the same result.

Any suggestions gratefully received.

Thanks,

John Jones