Re:Firefox (Score 1)

Actually if you check better what is going on at the HTTP level you find the bug. Just look at it using wget

Request: http://secunia.com/ie_redir_test_1
Answer: 302 with Location: mhtml:http://secunia.com/ie_redir_test_2

where MHTML is a special mime for storing a full web page in a HTML file. Then
the browser peforms the redirection

Request: http://secunia.com/ie_redir_test_2
Answer: 302 with Location: http://news.google.com/

finally a good browser should stop the forwarding because of the different domain, but
instead IE gets confused and grabs the external resource.