The red border above marks a simple object: <object data="/security/ie_iterate_freeze/index.php?emptypage=true" type="text/html"></object>. Click on "Iterate over object" to start the test. If an alert box pops up, everything is ok. It works by iterating over an object. IE returns the same keys over and over so it becomes an infinite loop.

Normal infinite loop (should be aborted after a few seconds) Iterate over object