[rules-users] where can I find the drl compiled java file?

Hi I am facing a weird problem where the rule works fine for the first time after I start the rule engine. After that, the same set of data causes the rule engine to give a nullpointerexception when firing the rule action. It gives the line # in the compiled java file, but I cannot find that file. The line # doesn't match the drl (obviously), so I can't make sense of where the exception could be occurring. So, where can I find this drl compiled java file? Thanks Shyam