I solved my problems :-)
I started a new installation. And this time I used a pure Debian linux - not a Ubuntu Server. There is no Java and no tomcat installed. I took the newest version from JDK and Tomcat directly from the distributer and installed it manually - not with apt-get installs. It was a little bit more tricky but now it works :-)
Debian 5.0 Lennyapache tomcat 6.0.18jdk1.6.0_12
manual settings:Important are the environment variables and the user rights for example at the jar-directories. Also important are the user rights in /conf-, /log-, tersus-server- and application - directories if you want to start tomcat as deamon. So you have to add a new user in the shadow and passwd in my case "tomcat6". And there are some settings in the tomcat start-script.
I want thank you for your help
For best results, use the Firefox browser..