Question : Sharepoint not sharing port80 with IIS Default WEbsite

I have recently setup (after much swearing and learning) Sharepoint 3.0 and IIS (RWW, OWA, etc) on port 80 using different host header values. Everything was working fine until I decided to setup incoming email and found that IIS had no default SMTP server although the component was installed in IIS and the service in SP was started.

Long story short re-installing the SMTP component of IIS replaced the Exchange one which required a repair of the Exchange sMTP server using smtpreinstall.exe which fixed that.

Back to Sharepoint and IE no longer loads Sharepoint or RWW,OWA, etc using IE but works fine in Firefox.

Setup is as follows:

Windows 2K3 Server premium (IIS, ISA, Exchange, SP 3.0)
Default Web Site (port 80)
Intranet (port 80 using intranet host header, runs SP 3.0)
Sharepoint Central Administration (port 29557, working fine)

I have checked that neither site is in trusted zones and look into alternate access mappings and changing the zone between default and intranet with no success. I have heard the problem can also be caused by NTLM authentication, I tried changing authentication to Kerberoes but with no change. I noticed that the default site decided to extend itself as well so I have removed that and tried re-extending the SP install but to no avail.

After the amount of problems I had getting it working at first I'd like tro save my sanity and time and try to find out exactly what I have done to have this happen again and how to prevent it in future.

Answer : Sharepoint not sharing port80 with IIS Default WEbsite

I can access the default web site through IE since it doesn't use a host header it responds by IP.

It turns out the problem was an ISA firewall rule that was causing the problem, something must of changed either through CIECW or some such after I fixed the SMTP virtual server. I should have double checked this VERY early on before I went on the other tangent, Occum's razor and all.

Now im confused as to why Firefox was working but not IE since assuming it was a firewall issue the whole time why one worked and the other didn't.