Tomcat software has the concept of multiple running Tomcat instances, and the way to handle that is using property catalina.base. In a single, traditional installation, catalina.base has the same value as property catalina.home. In a virtual hosts environment, catalina.base points to the instance directory where webapps is living, meanwhile catalina.home is only pointing to the software libraries and shared webapps (manager, for instance).
Also, real.catalina.home internal property usage should be replaced by catalina.base property usage.
So, a couple configuration and compilation files from Soaplab2 should be updated in order to use catalina.base instead of catalina.home. For instance, xmls/deployment.xml or xmls/tomcat.xml.
You have a couple of pages talking about catalina.base here:
http://tomcat.apache.org/tomcat-4.1-doc/catalina/docs/api/org/apache/catalina/startup/Catalina.html
http://www.jguru.com/faq/view.jsp?EID=1121565
change made as suggested, it will be included in the next release, 2.1.2, this June