I had the exact same problem. For whatever reason Shadowrun won't pull down the latest auto-update for some of us.

Download this and just install it:

http://www.microsoft.com/downloads/details.aspx?FamilyID=c975179c-dfbb-4a99-b0d5-7abf45d00c71&DisplayLang=en

The moment there is confirmation of this story, I will cancel my Gamespot subscription.

I'll never visit Gamespot or any Cnet affiliated website again, nor will I purchase an Eidos game. This is unacceptable!

Ratchet & Clank Future ;)

But seriously; I strangely enjoyed going through Bulletwitch.