MLB.TV has no clue.  I am trying to run either their streaming product with Silverlight installed, behind a proxy, and it will not request proxy authentication.  If I remove Silverlight everythign works fine; requests proxy authentication and stream is initiated.

Is there a Silverlight config file that can be editted to ensure that it requests proxy authentication?

I think that what MLB is doing is if Silverlight is installed, it is using it so when you uninstall it, its using their older Flash-based player.  There may be a bug with teh Proxy auth in Silverlight, perhaps someone with more video expertise will chime in.

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Shawn Wildermuth
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Yep, that is exactly what it is doing.  MLB does not offer an option to select with/without Silverlight.  I have had to remove it completely from the PC in order to ensure I could watch the feeds. Hope someone from Microsoft will chime in.  Seems like all we need is a proxy auth options in the config to allow it to prompt for authentication or use (correctly) IE's settings.