HELP: memory leak?

We have been experiencing an issue with what appears to be a memory leak in webMethods.

We are experiencing same problem in our Adapter. Disabling multithreading for the Adapter seems to help a bit, but eventually Adapter will run out of memory. Anyone knows source of the leak and or solution?
Does wM use thread local storage that is not cleaned up after request/document processing is complete?!
What is recommended max java heap size? I’ve read some forums that recommend to use 1GB, sounds too much if application(in stand alone mode) may need just 128MB?

We are investigating a memory leak in IS 6.0.1 executing in HPUX11. We are using 2.5 Giga and we have estimated that half of this value should be enough for the flows and services we have. After two days we have to reboot the server because we reach out-of-memory problem.
The grow of memory usage follows a pattern that lead our conclusions to a memory leak occurring in WebMethods architecture.
I would be very thankful if someone could give any information about the memory consumers of WebMethods architecture that I could monitor using tools as Optimizeit.