The stupid button at the end of the url bar in ie8 makes it behave like ie7 if clicked.
I bet half the people using IE8 have that turned on and they dont even know it. They put the button right beside the reload button where it's probably miss-clicked all the time. sigh. unclick it and restart browser to combe back to ie8
where do you work? perhaps the door that you walk through into your office is one of those Dr. Who time travel corridors into the past! Maybe you have IE8 and have the compatibility button checked on my mistake.