Why does Internet Explorer 9 have so many problems?

My computer is relatively new, but ever since Internet Explorer 9 was automatically installed, it's been having a ton of problems. There's this sight I like to go on called failblog(dot)org, and a message box frequently comes up and says Internet Explorer has stopped working. Also, I like to go onto newgrounds(dot)com, and I like to look at the art a lot, but now, I can't filter individual ratings, and when I favorite something, it takes me to this page that says I've added a favorite. It's stupid and annoying, and I want it to stop.