Windows Authentication Pop-up in Intranet

Hi!!

We're trying to setup an Intranet site with one portion of the site restricted using Windows Integrated Authentication. The rest of the site is accessed using anonymous access. Here are the details of the site

1) The restricted portion of the site is protected using NTFS permissions for authorized users
2) ONLY Anonymous user has NTFS permissions to the rest of the Intranet (all files / folders EXCEPT the restricted portion)
3) The IIS setting throughout the site has both anonymous access and Windows Integrated Authentication enabled
4) The restricted portion of the site is also the application start-point (in IIS) for an ASP application
5) The restricted portion of the site launches in a new browser window (using target="_blank")

Authorized users are able to access the restricted portion of the site. The problem is that when they try to get back to any of the anonymous access pages, they are prompted with the Windows Authentication dialog.

Is there any solution to this? Are there any web server settings that I need to look for?

Any help on this is greatly appreciated.

Thanks

Assuming you're using IIS, usually IIS operates as the IUSR_computername user. If this IUSR account doesn't have access permissions IIS will prompt for a username.