It could be an IDE bug; I used JBuilder X and had the same problem. If you do so as well, then you should install the JBuilder X Update 004 patch (download from Borland if registered) and follow patching instructions related to JBoss fixes
I am using Ant from the Cmd-prompt on Win NT .
Are your JSPs located at your webapp root dir or in subdirectories?
I've heard about building problems in second case. You can try replacing the jasper-compiler.jar and jasper-runtime.jar libraries you are curently using for building for older ones (could be 4.0)
I have fetched the latest Jasper.*.jar fromboth: apache.org and jboss-4.0.1 but still recived receives the error:"No public execute() in class org.apache.jasper.JspC"