I still have a sneaking feeling that every now and again during the installation, that sources.list file and/or the files in sources.list.d get slightly mangled...
Am I right in thinking there is some editing (or regeneration) of the sources.list file during installation? As I see that the ubuntu servers entries contain a country code of 'gb' (in my instance) which were 'us' on the Live CD sources.list file.
Can't find anything wrong huh Jack? :) I think it's time to stop beating this non issue dead horse... let it go. This release is exceptionally good. It's just that simple.