I think you need to replace the files in the theme directory with those from the 1.7.8.11 download archive. I suspect something hasn't been updated, but it's just a theory.
Can you look at the "Advanced Parameters-->Information" page in the Back Office and check if it comes up with a list of file changes (at the bottom of the page. It will take a little while to populate)? Just in case we're looking in the wrong place.
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I think you need to replace the files in the theme directory with those from the 1.7.8.11 download archive. I suspect something hasn't been updated, but it's just a theory.
But, can you look at the "Advanced Parameters-->Information" page in the Back Office and check if it comes up with a list of file changes (at the bottom of the page. It will take a little while to populate)? Just in case we're looking in the wrong place.