Hi,

e.g.
ezwebin/override/templates/full/article

Line 64
<input type="hidden" name="ContentLanguageCode" value="

{ezini( 'RegionalSettings', 'Locale', 'site.ini')}

" />

The wrong ini setting is read, should be:

{ezini( 'RegionalSettings', 'ContentObjectLocale', 'site.ini')}

Reason:
RegionalSettings / Local could be e.g. eng-GB@euro

This happens also in several other templates like forum.tpl, forum_reply.tpl, forum_topic.tpl

Best wishes,
Georg.