We have an intermittent login issue on one of our client websites that began about a week or so ago. Before that everything was working fine. The site is running on DNN 4.4.1 and uses a custom membership provider to authenticate against an external data source. Users are then added to one (or both) of 2 custom roles created within DNN. This is functioning fine - users are being created and assigned the correct roles.

The problem is when the user logs in they get an "error" stating "You do not have access to view this tab within this portal" but they do. If you check the page permissions and the users roles the same roles are selected on both. The user is getting logged in - opening another browser window and trying to login shows this, as does the Log Viewer. The error appears to be with DNN when it goes to display the user homepage - it is as if the request is coming from a non-authenticated user.

As I said this is an intermittent problem, the "error" will literally be displayed one minute but not the next. This affects all users (except the host and site admin) and all browsers (that we can get our hands on). We have tried changing the host settings in case the page is being cached but with no success.

An help would be much appreciated.