- <lastBuildDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></lastBuildDate>
+ <lastBuildDate><?php
+ $date = get_lastpostmodified( 'GMT' );
+ echo $date ? mysql2date( 'D, d M Y H:i:s +0000', $date ) : date( 'D, d M Y H:i:s +0000' );
+ ?></lastBuildDate>