Very Strange Log-In Pop-Up Window

Hi,

I am getting a really strange pop-up window every time I log-into the WordPress dashboard for my site. It reads:

To view this page, you must log-in to area “durangorollergirls.com” on durangorollergirls.com:80.

Your password will be sent unencrypted.

Name:

Password:

It goes away when I click on cancel (meaning I don’t actually have to log-in in the pop-up window). The really annoying thing is is pops up EVERY SINGLE TIME I do any sort of action in the dashboard – save a page, move to a new tab, make any changes at all.

Does anyone know how to get rid of this?

Thank you!