JRuby and Rails - running app not using changes

We're running IDEA 10.5.2 w Ruby plugin 3.2.4 - the project is setup with JRuby 1.6.5 and Rails 2.3.14. When we run Rails through IDEA, changes to model and controller files are not loaded automatically into the running Rails app (config.cache_classes is set to false in the running environment). This did work when using Ruby. Makes it pretty much unusable for debugging problems as you now need to stop and start Rails with every change.

Has anyone seen this problem? Is it IDEA? Is it JRuby?
Any ideas appreciated.

thx