Remote Web Workplace does not load - It says 'The page cannot be displayed' and also 'Loading' in the middle of Internet explorer

When we try and access remote web workplace on our sbsserver we get the message that the page cannot be displayed in the top left hand side of internet explorer and in the middle it says 'Loading...' This appears once the user name and password have been entered. Outlook web access is still working.

On the server we get an error from SBS.RWW which has event ID 0.
Below is the error message that appears:

The following fatal error occurred in the Remote Web Workplace application:
      URL:            http://sbsserver/Remote/header.aspx
      Error Message:      An operations error occurred
      Stack Trace:         at System.DirectoryServices.DirectoryEntry.Bind(Boolean throwIfFail)
   at System.DirectoryServices.DirectoryEntry.Bind()
   at System.DirectoryServices.DirectoryEntry.get_AdsObject()
   at System.DirectoryServices.DirectorySearcher.FindAll(Boolean findMoreThanOne)
   at System.DirectoryServices.DirectorySearcher.FindOne()
   at remote.RAPLinks.getCurrentUser()
   at remote.RAPLinks..ctor(HttpRequest httpRequest, HttpServerUtility httpServer, HttpSessionState httpSession)
   at remote.Global.getRAPLinks(HttpServerUtility httpServer, HttpSessionState httpSession, HttpRequest httpRequest)
   at remote.header.Page_Load(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain()

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Does anyone have any ideas what might be causing this?