permissions in G2

I am struggling to get my permissions right in G2. I am using "User Albums" if that makes any difference.

What i want is....

- for a guest to be able to view all the thumbnails of the root album but not enter the sub gallery's or change anything
- for registered users to be able to view all the thumbnails of the root album and enter the sub album which is assigned to them in "User albums"

I think I've tried every combination of permissions on both root and sub albums but I'm not getting the required results.

Any top tips out there?

Many thanks in advance

DP

Gallery URL = http://gallery.com/room4studio/gallery2/main.php
Gallery version = 2.3.1 core 1.3.0.1
API = Core 7.54, Module 3.9, Theme 2.6, Embed 1.5
PHP version = 5.3.6 apache2handler
Webserver = Apache/2.2.19 (Unix) DAV/2 PHP/5.3.6 with Suhosin-Patch
Database = mysqli 5.5.15, lock.system=flock
Toolkits = Gd, ImageMagick, NetPBM, ArchiveUpload
Acceleration = none/0, none/0
Operating system = Darwin mbposx.home 11.1.0 Darwin Kernel Version 11.1.0: Tue Jul 26 16:07:11 PDT 2011; root:xnu-1699.22.81~1/RELEASE_X86_64 x86_64
Default theme = room
gettext = disabled
Locale = en_US
Browser = Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:6.0) Gecko/20100101 Firefox/6.0
Rows in GalleryAccessMap table = 10
Rows in GalleryAccessSubscriberMap table = 17
Rows in GalleryUser table = 3
Rows in GalleryItem table = 16
Rows in GalleryAlbumItem table = 2
Rows in GalleryCacheMap table = 0