[error message - Failed to load the application. It was built with an obsolete version of Silverlight]

I am using VS2005 and Silverlight 3.0 and I get this message when I try to run one of the published ChartFX web examples.  (CfxSilverlightSamples_Web).  Can anyone tell me what I might do to get this to work?

[Chart FX 7 and 6.2 installs hang]

I'm experiencing a problem where the Install for 7 (and 6.2) hangs on the "installation requirements" screen.  Has anyone else had this problem?  I had CFX7 installed before, then I uninstalled, now I'm try to re-install, but no luck...