soap fault when executing loadtest !

Hello,

I've configured a datasource driven load test: 20 threads, simple, no delay, no random, 20 Total runs.

The datasource (csv file) contains 1 million records.
The loadtest executes fine.

However I always get a number of soap faults back from my application. These faults occur when soapui is kicking of the loadtest's threads. When I execute the loadtest with 20 threads I get about 19 soap faults, when executing the test with 30 threads, I get about 29 soap faults.

The funny thing is that at the server side the requests arrives and it seems ok. But still I get a message like the following:

<?xml version='1.0' encoding='UTF-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><soapenv:Fault><faultcode>soapenv:Client</faultcode><faultstring xml:lang="nl">XML validatie fout</faultstring><detail><spring-ws:ValidationError xmlns:spring-ws="http://springframework.org/spring-ws">cvc-complex-type.2.4.b: The content of element 'BijkomendeInformaties' is not complete. One of '{BijkomendeInformatie}' is expected.</spring-ws:ValidationError></detail></soapenv:Fault></soapenv:Body></soapenv:Envelope>

Did you already encounter this situation ? Is it a soapui matter, or is it a threading problem at the application side ?
The funny thing is however that once the loadtest is at full speed the soap fault doesn't occur anymore or only very few times, and if it occurs, it only seems for/due to a soapui thread that didn't lead to a soap fault yet.

I'll send a screenshot to the support mail adres.

Hope you can help, because production deadline is getting very close.

Thanks,
EDH