Typically a search engine representative would not reply to a thread where a Webmaster accuses them of penalizing a site for using a competitors service. In a WebmasterWorld thread, a member said that his site is suffering in MSN Search due to placing Google AdSense on the pages.
The WebmasterWorld members reply to the thread creator that his accusations are unfounded and wrong. But then we have a shocker, at least in my opinion, MSNdude (official MSN representative), replied to the thread!
That's certainly not by design. I suspect something else is wrong with your site to cause this. However, we'd like to check this one out -- just in case -- because if it really is our bug, it's very serious and we'd want to fix it immediately.
This is just not typical.
Forum discussion at WebmasterWorld.