After update from 6.0.1203 to 6.0.1367 i can use only one Internet Explorer window. The second open window freezes.
After uninstalling Avast everything is working again. After a new installation of Avast is a problem with browser back.
Avast Free 6.0.1367 (autosandbox off)
Windows 7 x64 Home (fully updated)
Internet Explorer 8
Sandboxie 3.50 (may cause problems…)