Bug in IE9 (set focus in input field via internetexplorer.application object)

I have some code that basically creates a COM internetexplorer.application object

I scan through the DOM, find a password field element and then do the following:

element.focus()

This line puts the cursor in that password field

This code works in all IE versions except for IE9. But if you click the Compatibility View button that is located directly to the right side of the address bar next to the Refresh button it works (because it sw开发者_C百科itches to IE7/IE8 mode)

I searched the net many days for an explanation, believe now that this must be a bug (or an undocumented change).

What is your opinion about this? Is that difference documented somewhere?