If you have heavily customized Outlook Web Access logon pages and are planning to install Exchange Server 2007 SP1 Rollup Update 3 (released last week) on your Client Access Servers, this post is a must-read.
After the upgrade, the OWA login page refused to show. The URL redirected to https://webmail.company.com/exchweb/bin/auth/owalogon.asp?url=https://webmail.company.com/exchange&reason=0&replaceCurrent=1 and all I got was a blank browser window.
So I pulled my wits together and started stripping any customization that’s not in the book. Once I removed the hyperlinked text that I had added on the logon screen, things started working again.