You may have seen the recent advertisements from Microsoft promoting Internet Explorer 9 as a great new browser platform--far better than all prior releases of Internet Explorer. However, even as a Microsoft developer, I have found that Internet Explorer 9 continues to leave a lot to be desired and will probably never be able to compete with the likes of Mozilla Firefox and Google Chrome.
Here is an example, I was recently trying to submit file attachments on Microsoft's very own website: https://connect.microsoft.com. Of course, considering that it was a Microsoft website after all and Microsoft's websites are notorious about having problems with supporting functionality in alternative browsers (just check out https://partner.microsoft.com and http://visualstudiogallery.msdn.microsoft.com in Google Chrome), I decided to use Internet Explorer 9 to attempt to upload my files.
Well, guess what, I could not even click the Submit button after attaching my files!!! I even switched to IE 8 compatibility mode and tried it again--still no luck!! So....I finally gave up and decided to switch over to Google Chrome. As you can probably figure out by now, it WORKED JUST FINE! I was able to successfully add my attachments and click the Submit button.
Moral of the story--if even Microsoft cannot get browser support for IE 9 right, why should it be considered to be so great???