I was trying this problem like you.(JSP Compiling using Jbuilder8 and Jboss3.2.5)
Following step is a my solution.
1.I changed JBuilder Library Setting. (Original:User>Servlet>Tomcat4.1 -> Change:User>Servlet>Jboss3.x)
2.I added libraies in Jboss 3.0 Server.(Libray Resource : Library of $JBoss_Home/Server/default/deply/jbossweb-tomcat50.sar)
3.I compiled jsp source with Jboss Servlet.
Of course. This method is not optimized method. but this is a working solution. ^^
I am sorry that I can speak english a little.