Permissions and Unwanted Login Prompt

Ok, I am new to IIS and I am learning ASP (althogh I am an advanced VB programmmer, so I am making good progress).
On the webpage that I am currently building (http://lozware.zapto.org), users who access the webpage from outside of my computer (eg via the internet) are receiving a login prompt. Co-insidently, this login prompt apperas just before the title image appears, and after the user closes the login prompt (not submitting a password) the image confirms that it has failed to load by displaying the red X inside it.
Now my first ideas where that I had not setup the IUSR_SAPPHIRE (my computer is called sapphire) to have sufficient privilages to read the image (/gImages/title.jpg). So I made sure that all of the permissions were correct, and still got the error. I even went to extremes by giving the IUSR account every access right imaginable - I even added it to the Administatrators group and still nothing.
The webpage is perfectly accessible via my computer on LOCALHOST, but otherwise, this problem occurs.
Check it out yoursulf...
http://lozware.zapto.org
The webpage will load, but you will see a login prompt, and upon failing the login, the Title.Jpg will not be displayed - everything else SEEMS to work.
Thanks,
Lawrence

does IUSR have complete access to the gImages directory where the image is located? Are you using Windows Authentication as well as anonymous user?

Here are some screen shots displaying that I have setup the IUSR account with every possible privilage, and the login prompt still appears (these property windows apply to the gImages folder, which is where the Title.jpg (which wont load) is held. Infact, all of the files/fodlers inside the wwwroot folder have these privilages.)...
IIS Setup
gImages Web Share
gImages Security Attributes

So......thats probably confused everyone!
Cheers guys, keep the ideas coming!

WHOOOOO I FIXED IT...
The problem is that I was 'sharing' the gImages folder. Although you must 'share' the root dir (wwwroot), if you 'share' a sub-dir, then that folder wont be accessible, weird I know, you would have thought that it would be the other way around - good ol' backwards microsoft. Well I'm happy coz I got it working. So...
BOTTOM LINE:
1) Set the Root Dir (normally WWWROOT) to 'Share This Folder' under the Web Sharing tab.
2) Set all of its sub dirs and files to be readable by the IUSR_COMPUTER account (and writable if your webiste contains scripts that write to files)
3) Make sure that you DO NOT share any of the root DIR's sub-folders, otherwise they WILL NOT be accessable.

good to know ... glad you got it working

I have seen many people that have had this problem when looking through google, and it has always been un-resolved. Hopefully they will come accross this forum and this thread - as it took me a good 2 days to work out what was wrong.