Yes, sorry, this is a well-known problem. We are looking forward for full Java 6 support on Mac. In the meanwhile we are just compiling all libraries with Java 5, but still it seems we have some problems on the Mac.
As none of our developers has a Mac (either Linux or Windows) we are not able to test it ourselves. So if you could provide some more logging information, then we aim to improve AgilPro for Mac, too.
Alternatively, you could download the Eclipse JWT plugins into your Eclipse. Then you will be missing some parts of AgilPro LiMo (such as the code generation for BPEL), but the other things should work. Please have a look at http://wiki.eclipse.org/JWT_Downloads for further information.

Best regards,

Florian