Hi, when you set a center, the plugin also expects you to set the zoom – you can use the ‘zoom’ parameter to do it. I went to that page and it looked OK, so maybe you already did that? If not, something like this might work:
[mashup width="100%" query="posts_per_page=25&category_name=members" directions="none" center_lat="-32" center_lng="122" marker_link="false" zoom="5"]