Having tried to upload and install the zip file with error messages after several attempts I read that there was a problem with PHP 4 so I went for the latest nightly build (679) to see if any progress had been made. Simple answer is no, not yet. Had a partial success with 1.13.1 which appeared in the components list but a click on the RSGallery2 link came up with this:-

Warning: main(/share/storage/01/fr/frizzell/nmids/administrator/components/com_installer/installer.class.php): failed to open stream: No such file or directory in /share/storage/01/fr/frizzell/nmids/administrator/components/com_rsgallery2/includes/gallery.class.php on line 11

Fatal error: main(): Failed opening required '/share/storage/01/fr/frizzell/nmids/administrator/components/com_installer/installer.class.php' (include_path='.') in /share/storage/01/fr/frizzell/nmids/administrator/components/com_rsgallery2/includes/gallery.class.php on line 11

My ISP is still using PHP 4 and not showing much sign of moving to PHP5 yet so am stuck with it for now. Willing to keep trying new versions on my server but my knowledge of all things Joomla isn't great. (Even less knowledge of PHP)

As far as I can tell yes, permissions are correct 755 (777 not allowed with my ISP) Just looked through them but still same error messages.