syntax error reported if first line of class is a comment

This seems to be happening in many if not all of my Grails classes. If the first line inside class definition is a comment then IDEA/JetGroovy reports an error on the first character of the non-comment line. The reported error is: ',', '}' or new line expected

Here's an example:

class DeliveryController { // some comment def someService ... ]]>

The code works fine if I execute 'grails run-app' from the command line, and JetGroovy does not report an error if I reverse the lines, e.g. put the line with def before the comment line.

I'm using JetGroovy 1.5.16212.