I have one issue that I have noticed with my MCE2005 install. Maybe some of you have seen it as well???
When browsing by cover art I can see all my albums with no problem. (about 600) BUT If I browse by artist, some of the albums that I know I have for that artist do not show up but if I switch to the "Show Songs" under that artist it will show the songs from the missing albums!!??!!? WTF???
Now don't try to say it's my tags because it's not. I'm very anal about the tags and ALL of the albums showed up properly in MCE2004.