Site password authentication pops up - for a completely different website!

Hi:

I have a very strange problem.  When I go to www.OregonIR.org, I am prompted via directory password protection to enter the username and password - for the website fastecs4 com.

Both are Drupal sites and are hosted on Hostgator, but are on different servers.

Both are my sites.  I did password protect the document root directory of fastecs4,  but not oregonir.org. I did the password protect via the hostgator control panel, which added authentication statements to .htaccess.

The problem exists under Firefox, Opera, and MSIE under Win XP pro, connected to cable via a hardware router. The problem exists on at least one client computer in Oregon.

I rebooted the PC and the router, cleared cache and cookies for the two sites, but the problem remains.  

When I remove .htaccess on the oregonir site, the problem remains. When I remove .htaccess on fastecs4, the problem goes away.  I removed index.php on each site and the problem remains, so it probably is not related to Drupal databases. So it appears that somehow the websites are getting cross-connected at the PC level.

The problem does not occur when accessing the site via the www.pagewash.com anonymizer.  It does not occur when hostgator support views oregonir.org, nor when an independent user views the site under windoze / chrome.

My concern is that this problem may be affecting lots of people who browse the oregonir site.

Suggestions would be greatly appreciated!

Thanks,

Fred