How to let the googlebot see pictures?

[Stefan118]

Somehow I can't change it back to let guests see the thumbnails and download attachments!

What i have done is this:
AdminCP --> Usergroups --> Usergroup Permissions --> [Edit] Unregistered / Not Logged In
Use Usergroup Default Permissions -- Yes -- Saved!
I got the message:
Deleted forum permissions sucsesfully

AdminCP --> Usergroups --> Usergroup Manager --> Unregistered / Not Logged In --> Edit
Forum Viewing Permissions
Can Download Attachments -- Yes
Can See Thumbnails -- Yes
Saved!

Now the group is back to original and has the color of: Standard: Using default usergroup permissions

What am I doing wrong, or what do I forget?
When im not logged in i still can't see the thumbnails, and when i click on the name of the image, i get the error message:
You are not logged in or do not have the rights to ..............

Now help is realy needed!