Thread group (1 loop - 1 thread)
    User defined variables (http server name and port)
    HTTP Authorization Manager
    WebService(SOAP) Request
       Response Assertion
    WebService(SOAP) Request
    WebService(SOAP) Request
    WebService(SOAP) Request
    View Results Tree
    Assertion Results

For the 4 requests, server ip, port number, path and SOAP Action are the
same.
By default, when creating a Web Service request, "Memory Cache" is checked, but
I think it means to cache the SOAP data across the same request in multiple
threads, not that all requests will share the same SOAP data.

The Soap/XML-RPC data changes only in the <email> part.
I am going to attach the file, where 
request 1 is a positive test case
request 2 is a negative test case (searching for an email address not present in
the database)
request 3 is a negative test case (issuing the request without the required
parameter)
request 4 is a negative test case (issuing the request with a wrong data type)

<soapenv:Envelope
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/";
xmlns:xsd="http://www.w3.org/2001/XMLSchema";
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";>
        <soapenv:Body>
                <ns1:findCustomerByEmail
soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/";
xmlns:ns1="urn://mobility-platform.de/mpcustomerdb/">
                        <email xsi:type="xsd:string">[EMAIL PROTECTED]
                        </email>
        </ns1:findCustomerByEmail>
        </soapenv:Body>
</soapenv:Envelope>

When I run the test case, the same SOAP content is sent for all the 4
requests.
I have verified the behaviour by running through a proxy.

In general, it looks like there is something strange with the WebService
requests when "Memory Cache" is selected: for example, if I change the order of
the requests, I have to close and reopen the test plan for the change to take
effect.

Server is running Debian Linux, and the webservice is Axis.
On the client, I am running Suse 9.3, Jmeter 2.1.1 and JDK 1.5