We are familiar with such problems but we still officially don't support IE9 (we don't support browsers in BETA stage). Of course, we work on the issues that we discover with the previews, but in general we prefer to wait until the final version is out before making any serious modifications in our code. Once IE9 is officially released, we will publish a service pack that provides support for the new browser as soon as possible - usually no more than a week after the browser is out.
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