Access masks added but users cannot post

[nambisolo]

Hello

I have a requirement to provide access to a particular forum on a per user basis. These users belong to a variety of primary usergroups and are not a group in their own right. I understand per user access is implemented through the use of access masks. I have access masks enabled in the general settings. I have edited the access mask for each user via the quick user links in their user profiles. This has allowed the users to see the forum but not post to it. How do I give these users permission to post?

Thanks.

Mike