I'm trying to insert the louver that comes with Solidworks and when I drag it over from the Design Library to a simple plate that I've already added the Sheet-Metal feature to, I get the following error: "Are you trying to make a derived part?" If I say Yes, then it starts the derived part process (bad). If I say No then it simply opens the louver in it's own window. At no time do I get the preview that I recall seeing in 2004. Anyone know what stupid mistake I'm making here?