Several customers are reporting issues since installing rollup 5 which is not uninstallable:

• Workflow based Organizations (many levels deep)
• ADFS / IFD Deployments
• CRM Email Router and Outlook Clients ( Cannot access the webservices)

A hotfix was originally released but now has been disgarded. Micorosft has now released UR6 to fix some of the issue(s) introduced with UR 5.