Odd - it's obviously a problem with yahooapis, which runs fine on my browser. Might be a one-off script error, have you tried it again recently?
All the HoM site uses is yahooapis and the ever-present google-analytics, both of which are widely used throughout the internet. If it's a persistant problem, you'll need to look at your browser. Is it the latest IE, or is it something sensible like the latest firefox or Chrome? Whatever it is, make sure it's updated.
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