I ran into an interesting problem today with a brand-new installation of CFMX 7 on Windows 2000 / IIS 5. The server had just been updated with SP4 and all the latest security patches, including URLScan for IIS. After installing CF, I tried logging in to the Administrator, but kept getting a 404 "Page Cannot be Displayed" error when I submit the form. After some troubleshooting, I deducted that the problem wasn't with CF at all, but actually with IIS. I searched around for some clues and eventually came across the configuration settings for URLScan. I found the urlscan.ini file in C:\WINNT\system32\inetsrv\urlscan and added "POST" to the list under [AllowVerbs] and then restarted the IIS Admin service. Everthing seemed to work fine after that.