loadUI agent 2.1.0 unable to resolve custom class

Hello,

I have the following problem and I am looking for a solution:
I created a new extension library for soapUI that is basically a Groovy class compiled into a .jar that I put in the folder [soapUI home]\bin\ext. I called this library Common.jar.
Then I copied the same library in loadUI ([loadUI home]\ext).
I can perfectly run load tests in local using this library, but as soon as I go distributes, the loadUI Agent launches the following exception:

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
Script1.groovy: 1: unable to resolve class Common
 @ line 1, column 14.
   def common = new Common(log, testRunner)
                ^

Exactly same thing happens if I use a script library (http://www.soapui.org/Scripting-Properties/scripting-and-the-script-library.html) in SoapUI Pro.

Is there any way to reuse code in SoapUI that loadUI agents are able to run?

Thank you very much!