ok, it looks like the user having the issue was trying to upload 6-8.5MB files through internet explorer in windows 7. We've tested using these parameters without reproducing the issue.    Can you explain how anti-virus or firewall issues might apply to this and how to diagnose the issue further?

One of my users is also seeing this error on our live site. Nothing is showing up in the unhandled exception logging that we have setup for the site (Global.asax > Application_Error). I've yet to get any diagnostic information from the user, but I will add that when I do. It's on a pair of load-balanced servers. I am not seeing anything ...

Is there any way for me to add a param of background=transparent to the silverlight that gets genereated?    Background: Apparently, it is causing an issue in internet explorer where the button flashes when i have a jqueryui dialog open.   Thanks, Colin