– as mentioned, they’re often used to solve problems that have nothing to do with content management.

– you tend to see a lot of extra CMS features enabled where there’s no natural “fit” for them (e.g., just because your CMS makes it easy to add a chat room to every web page doesn’t mean that every web page should have a chat room).

– I see far too may recognizable content management systems. A CMS should be invisible to the end user, not instantly identifiable (for whatever reason).

I guess those aren’t really problems with the actual CMS… just with how people choose to use them.