This is the result of a patent infringement lawsuit by Eolas and the University of CA (Didn't we beat them in football?) against Microsoft. UC patented a process to automatically enable embedded web content such as Adobe, Flash, ActiveX, etc.
Microsoft included a patch to remove this automatic behavior in a rollup of critical updates that includes several vulnerability fixes (MS06-013
- be patient if you wish to read this article. It will open in a separate window and can be rather slow to load.) that can't be ignored due to current exploits. Those interested in further information should search Microsoft's Knowledge Base (or KBAlertz.com) for KB912945
Even though KB917425 provides a file to disable this behavior, you should not install this update since it is only a temporary fix and may hinder future updates to your workstation.
To use the control, simply press the spacebar, press enter, or click inside the box.
There is presently no workaround for this problem. Aren't frivolous lawsuits wonderful?