This is one of the reasons I don’t use Ubuntu. Although I suppose it does make things easier for the average person on the street.
By the way, it’s “best practise” to issue “su -” rather than plain old “su” (or, in ubuntu: “sudo su -“. The dash at the end forces root’s shell configuration to be loaded. It also changes the current directory to root’s home directory.
This way you get all of the extra shell settings etc. you use as the super user. (hmm – a few aliases might come in useful as root!)