SSRS 2008: Assign domain to role not working

We have several reports that will be seen by our IT group which is composed of 30 users. The domain name is ITGROUP.

I assigned ITGROUP\jsmith as "browser" (user jsmith) and he was able to see the report. But if I assign ITGROUP as 'browser' (the whole group) nobody in the group can see the report.

What can the problem be? Once I add it the domain to the role, I see two rows:

BUILTIN\Administrators        Content Manager
ITGROUP\                      Browser

But the users under that domain still cannot see the report.

Any help is appreciated.

Thanks.

VM