It doesn't seem to me that jbpm.sar is hot-deployable .. due to the embedded ehcache.jar (1.2.2 with AS 4.0.4), which fails to load any config xml after jbpm.sar is replaced. And if this is the case, then ehcache.jar should be deployed under "lib".
However, I do like a self-contained sar (to ease deployment), and wonder if anyone has other expriences or work-arounds.
I'd tried to extend jbmp.sar a bit to support dynamic db-schema creation.
the sar is going to be replaced by a jca compliant thing so it is the same on all appservers. So not sure if this will get a lot of attention