Exception when using soapUI Runner
I have a loadUI 2.1.1 project which runs two copies of soapUI 4.5.1 test case simultaneously (two separate soapUI runners each connected with its own fixed rate generator). If I set the request rate of both generators to 5 requests per minute or more, very first test run (for instance, just after the loadUI starts) always fails with a following exception (don't have access to log right now, so there can be some mistakes 
):
To be more precise, I use two WSDL's in a soapUI testcase: all requests to a first web service are performed without any problem, but first request to a second web service fails with previosly mentioned exception (this request has a Schema Compliance assertion). Test fails only once, and all next runs of test are successfull: for example, 2 generators, 5 request per minute, running for one minute - 9 successfull test runs and 1 failed; and if I run the project one more time (without restarting loadUI), all 10 runs will be successfull. Both web services are running locally on a development machine.
Is this a known bug, or maybe I have some problems in my test?
):NullPointerException at com.eviware.soapui.impl.wsdl.support.wsdl.WsdlContext.getDefinition (WsdlContext.java:71)
at com.eviware.soapui.impl.wsdl.WsdlOperation.getBindingOperation (WsdlOperation.java:754)
at com.eviware.soapui.impl.wsdl.support.wsdl.WsdlValidator.assertResponse (WsdlValidator.java:597)
...
To be more precise, I use two WSDL's in a soapUI testcase: all requests to a first web service are performed without any problem, but first request to a second web service fails with previosly mentioned exception (this request has a Schema Compliance assertion). Test fails only once, and all next runs of test are successfull: for example, 2 generators, 5 request per minute, running for one minute - 9 successfull test runs and 1 failed; and if I run the project one more time (without restarting loadUI), all 10 runs will be successfull. Both web services are running locally on a development machine.
Is this a known bug, or maybe I have some problems in my test?