I have exactly the same problem, try to open anything in a new window and nothing happens, click on 'stop' and then 'refresh' and the window will then open, same with windows that try to open themselves Java windows won't open either, which makes some sites and services impossible to use. I've been through everything that MS suggest on the page mentioned in caperjacks post, but nothing has changed, all Registry entries/values are correct, re-loading IE6 doesn't help either, the problem still persists.
