Judy, you should now be able to open the XPages Forum on the server Notes1/Notesweb or Notes2/Notesweb using your Notes client.
For some time we have been running that forum only with native XPages rendering in the Notes client. With that setting the experience in the Notes client is the same or similar to using the forum in a web browser.
But as you reported previously not every Notes client is capable of opening that forum in that mode. This is due to our use of elements from the XPages Extension Library, which also needs to be present in your client install. Since most of the users of the XPages Forum also have the extension library locally, few if any people reported this as an issue.
But since you followed up on this matter we have disabled the native XPages mode for Notes clients and you should be able to open it successfully. You can email us directly at dwlotus@us.ibm.com if you need more help.