Ok.
I should have read your first post properly…
It seems that you have installed everything needed to run Alfresco, then downloaded and are trying to use the 'alfresco-1.2.1-linux-community.bin' distribution. This distribution contains everything needed to run Alfresco, including its own MySQL and Tomcat…
Because you have these previously installed, and running by the looks of your posts, you are getting conflicts.
I would suggest you stop all your previously installed Tomcat and MySQL instances before you start the Alfresco bundle.
Steve