The trouble which exists in 2.0.7, 2.0.8, 2.0.9 was improved.
Fixed bug: Custom Query which uses 'order' or 'orderby' parameters is preferred.
It does not depend on the designation manner of arguments( Parameters ).
$args = 'orderby=&order='
$args = array( 'orderby' => '', 'order' => '' )
From 2.0.6 please update in 2.1.0.
Because Fatal performance problem was improved dramatically in 2.1.0.
Please try this.