Some IE add-on is messing up things. To find out, which one....
Open IE normally, go Tools>Internet Options>Advanced tab, and click "Reset" button.
This will disable all add-ons.
Restart computer. See, if you can access sites in question.
If you do, start enabling add-ons, one-by-one, restarting IE each time, and checking troubled sites access.
Do so, until you'll find the culprit.