Since I upgraded to IE8, I’ve been a bit annoyed with the this security warning:

It states: “Do you want to view only the webpage content that was delivered securely”. The first time I just pressed Yes, by pressing [Enter] on my keyboard (without reading the warning correctly), which obviously rendered me a incomplete page.
Note to Steve Balmer:
Why change this button press behavior Microsoft, just to let us read dialogs? It will cost time every time we have to read such a dialog, and as you know.. time is money
Since then the warning came up a few times. So I’ve you want to disable this warning the change this:
in IE8, go to [Tools], [internet options] , [security] , [custom level]
and change [display mixed content] to “enable”

Settings will take effect after a restart of IE.
*edit after comment
I’m not saying that you should disable the warning. If you find it annoying, you can disable it.
The “old” dialog was different:
As you can see, this is the other way around. The changed it.
What you do with it is your choice.