Last modified: 2009-07-20 06:00:41 UTC
The log page headers, defined in $wgLogHeaders, are not shown at Special:Log. It seems that LogEventList::showHeader() is broken because LogPage::isLogType( $type ) returns never 'true'. A short investigation (not more time atm, sorry) shows that $type seems to be a wrong data type.
*** This bug has been marked as a duplicate of bug 19596 ***