I'm also testing the OTB geometry service on AGIS 10.1. I'm getting errors, so I've tried to confirm the tool is even hitting my geometry service but I can't see any activity on my services. I've even shut down the geometry service and used the standard draw tool to see if that works or throws an error. Oddly enough, with the geometry service url commented out of the config file, and my service shut down, I still get results??? Anyone have a theory for me?