1) Open Internet Explorer
2) Click on Tools
3) Click on Internet Options
4) Click on the Security Tab
5) Click on the Custom Level button
6) Under the Miscellaneous section look for "Display Mixed Content"
7) Click on Disable for Display Mixed Content instead of Prompt
8) Click on OK twice
9) Close Internet Explorer and reopen
10) Open the webpage that was displaying the warning message, the message should not appear now.
from
http://www.pchell.com/support/secureandnonsecurewarning.shtml