IIS asking for Authentication

I've got a bit of a strange situation here. I'll give history:

6 month old Dell Poweredge 1850 (RAID 1 with 2 drives)
Windows 2K3 (Standard Edition)
1 drive is showing degraded (will be replaced today)

With a degraded drive, website in Virtual Directory under Default was working fine from the outside as well as in. IIS Settings:

Impersonating as IUSR with Windows Auth on
Application directory has modify for IUSR/ASPNET and Read for everyone
Access to other folders necessary is set correctly setup (INETPUB, Microsoft.net/Version and Temp. Int. Files...)

As I said this was working. Then, I installed an ftp server in IIS as well as BITS, and opened port 21/23 for ftp on the router (DLINK 804...). Now, I can't get to the web page from outside without entering credentials. I've uninstalled both BITS and the FTP server and taken the ftp entries off of the router. Does anyone have any suggestions for trouble-shooting?

Thanks much,
Eric

Any opinions on whether this could be the degraded drive or not?

Perhaps the FTP setup changed the IIS authentication settings. Look around in the IIS manager is my first thought.