I think I found the cause of this (which has been irritating me for a long time too!) - can you try editing the file administrator/components/com_jevlocations/view.html.php and change line 689 from
$mainframe->redirect($googlemapsurl . "/maps?f=q&ie=UTF8&t=$maptype&om=1&q=" . $subtitle . "@" . $lat . "," . $long . "&ll=" . $lat . "," . $long . "&z=" . $zoom . "&iwloc=addr");
to
$mainframe->redirect($googlemapsurl . "/maps?f=q&ie=UTF8&t=$maptype&om=1&q=" . $subtitle . "&@" . $lat . "," . $long . "&ll=" . $lat . "," . $long . "&z=" . $zoom . "&iwloc=addr");
Does this help?