I was surprised to receive a "Property value is not valid" error dialog when assigning a Ruleset to a Policy activity. There was nothing particularly unusual about this action other than the fact that the workflow itself seems to be pressing the limits of what my poor 1.7 Mhz Centrino Duo CPU with 2-gig of RAM can handle (350+ activities, 1000+ rules). The dialog box wasn't my biggest surprise though… upon clicking the details button, I discovered that the source of the error was being reported was an "OutOfMemoryException!" egads! This would seem to imply that the WF designer is catching and eating all exceptions from this property setting--and assuming that any and all exceptions are a "Property value is not valid" error.  Tisk, tisk , tisk! Bad code monkey! Bad!