angular/angular.js — pull request #649 by nateflink (2011-11-10 21:21:49+00:00)
Title: I discovered that IE7 and IE8 throw a javascript error on delete window[...

I discovered that IE7 and IE8 throw a javascript error on

delete window[callbackId];

The specific IE7/8 error reported is:
Message: Object doesn't support this action

Doesn't seem to be a problem in IE9, Chrome, or Firefox
thanks guys, you rock!