Debugging plugin in Irida

I seem unable to debug a plugin though i have followed the instructions at http://www.intellij.org/twiki/bin/view/Main/PluginTesting firstly i couldn't find a idea.lax, so edited the batch/properties file, i tried the first option starting idea from the myidea.bat and though i seemed to get everything going, properties set correctly, i kept getting the only one instance of idea can be run at one time error message, using the installer set up explanation i get the same error message. I have searched the forums but have not found anything, can anyone help?

Cheers and thanx