I have similar problems with IE9. I removed IE9 and went back to 8 and the re-installed IE9. Problem is still there. The website shows very poorly (like no stylesheet). Sometimes I get asked if I want to download sparkfun_com… Most likely an issue on my side but I did reset everything I could possibly think of (security, etc…). Website is OK with Firefox in an Ubuntu VMWare machine. Does not seem to happen on other sites (I randomly web browse quite a lot)