Ignore if you have already exercise these suggestions
!) try scaling jBOSS AS itself. Play with mem args in jBOSS.
2) Try to reduce WAR size.(If multiple WAR are using same libs ).
3)Possible reason for permgen is memory leak(Its hard to detect ..Give it a go)
As an addition to suggestion (1), the permanent generation heap (which holds objects such as classes and methods) can be adjusted by setting the -XX:MaxPermSize option in the Sun VM. Look at the VM Options for details.
The permanent generation heap goes up because the port components published by the BPEL processes load Java classes that correspond to the XML Schema types referenced from the WSDL descriptions.