If you visit this blog with IE7, you'll get a topbar thing that tells you that the site wants to run the “Windows Media Player Extender” ActiveX control.
Since I did no such thing, I have no idea what is causing this. Of course I could voodoo debug the site and disable everything one by one until the culprit reveals itself, but I'd rather have you, dear readers (especially you webdevs out there) tell me what the problem is.
Prize for the winner. Well, maybe not, but you'll get my thanks anyhow :-)