It isn’t widely known, but with IE9 open, press the F12 key. It will open a developer’s panel along the bottom of the screen. I’m not home and am replying on a cell phone, so can’t refresh my memory. But in one if the tabs you will see a choice of which rules to run the browser. You can choose IE8. Also, IE8 should still be on your computer. A fresh copy should have been installed with IE9. Click the Start button, then look in All Programs. There should be links to both versions.
Wow! You learn something new everyday! Thanks so much!