Having problems to load images in Opera Browser(login popup)

I think this should be releated to IIS settings but don't know exactly what it is.

As you can see below, this login message pops up for each images, 8 images 8 times in Opera. login window

And the major browsers react to this page different.

IE9 works good(this is the reason why I found this problem now. It's internal site and almost every users use IE...)

Chrome(17.0.963.56 m) works good.

Safari(5.1.2) is also good.

Opera 11.61 has a problem like I said...

And FF SHOWS NO IMAGES and don't even ask for login. And Firebug says it's "NetworkError: 404 Not Found!". enter image description here

I don't know what's going on.

This site requires to login and it's internal, so I can't give you the link. Sorry for the inconvenient.

And this site is running on Windows Server 2003. And the image containing folder is shared for web(I don't know why it's shared. But don't want to change the setting). I don't know this may cause this situation. enter image description here

Solution

If Opera opens a user name/password dialog, the site is probably sending a WWW-Authenticate header in response to those image requests. You can open Opera's developer tools ("Tools > Advanced > Opera Dragonfly" or right-click in page and select "Inspect element") and use the network feature to inspect the full headers.

I don't know how you can disable this header if it is sent, it depends on the server settings and what type of server you're running, and I'm not at all familiar with Windows Server 2003.