As you might know Live Communications Server 2005 SP1 is now supported on Windows Server 2003 R2 and SQL Server 2005 SP1. Besides SQL 2005 SP1 it is also a requirement that you install the hotfix documented in KB911996 (Note the quirky installation procedure and that uninstall equals reinstall of LCS!!).
This time I was scripting the complete installation of LCS using LcsCmd and LCServer.msi (It's way easier to document, than "screenshooting" the GUI installation) and I also had a clustered SQL 2005 installation as a Backend Server.
After the installation I wanted to launch the LCS MMC on the Enterprise Edition front-end server, but it only presented me a window with the orange "Live Communications Server 2005" logo on top and a text in the middle "Live Communications Server 2005" - but no navigation pane.
I suspected it was either the scripted installation or SQL 2005 SP1 that was causing the problem, so this was where my trobleshooting efforts went. Two hours and a keyboard later I tried to open the MMC snap-in and manully add the Live Communications Server snap-in and voila, the navigation pane was back ;-)
I later chatted with one of my few contacts at Microsoft that really know LCS (You know who you are - and I'll keep my promise ;-) and was told that this was a "known issue", which they are investigating (Which is fine with me - since that means that my clustered SQL installation and installation scripts work as expected).