Bingbot throwing Validation issues with Request in ASP.NET / IIS7

Question

I am using ASP.NET MVC 3 on my site, but get these strange errors in my logs when Bingbot comes to crawl my site. Anybody else seeing this problem and know of a solution (not turning of Validation is probably not a good idea)?

Do I have something misconfigured or do I need to change something so my site plays nice Bing?

System.Web.HttpException (0x80004005): A potentially dangerous Request.Path value was detected from the client (:).
     at System.Web.HttpRequest.ValidateInputIfRequiredByConfig()
     at System.Web.HttpApplication.PipelineStepManager.ValidateHelper(HttpContext context)

Answer 1

We have seen this and looking at the IIS logs told us it was indeed a known issue with BIngBot appending " ForceRecrawl: 0" to well known URL's on the site. Also discussed here in the Pro Webmasters site