301 Redirect is defeating button click

I have a 301 Redirect in web.config that looks like this:
<rule name="Default Document" stopProcessing="true"> <match url="(.*)default.aspx" /> <conditions logicalGrouping="MatchAll" trackAllCaptures="false" /> <action type="Redirect" url="{R:1}" /> </rule> The purpose of it is to make requests for http://www.mydomain.com/default.aspx appear as just http://www.mydomain.com. It works as it should, and this is code I've found suggested in many places. 
But there's a big problem. It stops click events from happening at all. Even when I've reduced the code to just a button, the click event doesn't fire unless I comment out the redirect. The page will refresh on the button click, b ...