as per Oscar's report on the mailing list, see http://markmail.org/message/ilow6jkg5iuxbzis
Looking at the code, it does seem that we are leaking memory by not holding the ProxyFactory class  (we create a new instance each time).
The Javadoc  does suggest that these should be cached (it is the deafult).
One subtlety: the ProxyFactory is per class being enhanced. So we actually need to hold a cache of these. But at least then we will only get one extra enhanced class in the permgen per type, rather than per instance (as at the moment).
While we are here, we should probably delete the cglib support, and do some inlining of redundant interfaces.