I have similar problem.
1. I create Web Service test in Soap UI (Windows 7)
2. I create Load Test based on this test in Load UI
3. I run load test in local mode and observe resource utilization. Increasing load increases utilization.
4. I deploy agent on Fedora OS, connect it in controller and it connects (at least Load UI controller displayes icon that it is connected). I run test in distributed mode and resource utilization on the agent machine is not changing while I change number of threads.
LoadUI claims that agent is connected and requests are sent, but resource utilization is stuck on agent machine. I tried from 1 to 3000 threads per second - result is the same.
How do I debug such issues?