Large plugin based industrial automation application (STARDOM) is leaking java heap memory in 1.4.2_10 and prior versions. After 3 hours running in a stress mode, the heap size reaches 96 Mb and OutOfMemoryErrors start getting thrown.

Same application works fine with 5.0 and heap stays under 20 Mb after continuous running.

Examining the application in OptimizeIt, one big source of leakage can not be detected. Instead there are lots of small leaks.