Re: Where is the page?
There is something flaky going on with the bp URI hijacking. I had a page with the permalink http://ourcommoninterest.org/groups
Installed bp trunk 504 and when I select Groups from the member dropdown or from the bp member theme selection Groups, which is http://ourcommoninterest.org/members/admin/groups
Selecting either of those gets my Groups page in wpmu. Changing the page permalink to something else solves this.