You might want to check IE compatibility mode. I've seen similar things with it turned on.

>As of sometime this morning, UT will not open in my IE9 on my win7 machine that I use daily. If I try to open www.levelextreme.com I just see the IE spinning progress indicator for perhaps 30 seconds and then apparently the request just gives up - I stay on whatever page I was on prior to making the request. No error message or anything.
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>I opened it in chrome (on the same machine) just fine. That is what I am using to compose this.
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>Is it just my browser?
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>I've cleared temp files several times this morning w/no effect. I hate clearing cookies since that affects many sites.