The proxool driver inhibits garbage collection of the
ClassLoader which loads it, e.g. WebappClassLoader in
tomcat. This appears to be because proxool contains
older forked copies of cglib and log4j inside itself.
Those libraries have since been patched to correct
those and other problems.
Suggest incorporating the new code or, preferably,
switching proxool to link against external libs instead
of embedding copies in its own namespace.