When you are trying to create an audience based on a membership of an Active Directory group and that group is located in a domain in another trust.......quit trying, it won't work. This can only be done with a workaround.
I have been in contact with Microsoft Support and they wrote me the following:
You have two Windows 2003 Active Directory Forests. Two Domains in these Forests are trusted (External Domain Trust, no Forest Trust). You have given some users from the External Domain permission to access SharePoint. This works so far. Now you want to create an Audience based on the membership of a Group in the External Domain.
You cannot compile this Audience. You receive the error:
One or more values typed on this page are not valid. Check the text for the indicated fields.
This is as Design Limitation of SharePoint. SharePoint cannot read across the own Active Directory Forest because of the technique used to access it.
The work around this Design Limitation follow these steps:
1. Create a Domain Local security group in the Domain where SharePoint resides 2. Add *users* from the External Domain domain to this group 3.
Create a Audience with a rule specifying the Domain Local group created in step 1 4. Compile the audience
So just create a local group in the Sharepoint Active Directory and add the users of the other domain to that group. Audience compilation then will work and users are added to the audience!!