Tiberion

Find the following snippet in the tiberion theme header

<script>
jQuery.backstretch("<?php if ( is_single() ) {
get_image_url();
}else{
 $default = get_option('tiber_default'); echo $default;
}
?> ");
</script>

............and change it to the following

<script>
jQuery.backstretch("<?php if ( is_singular( 'reviews' )  ) {
get_image_url();
}else{
 $default = get_option('tiber_default'); echo $default;
}
?> ");
</script>