asp mvc iis7 debug mode errors page outputs unreadable characters

I'm running an asp.mvc web application on localhost on iis7 (win7) and I don't get my normal yellow screen of death with the call stack. I always get a page full of random unreadable characters. H开发者_如何学JAVAas anyone ever seen this? How do I get my callstack back?

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You might find the following blog post useful. You are probably using gzip.