Requirement_Retrieve, SOAP API

Hi,

I have a problem using the Requirement_Retrieve and RemoteFilters.
I try to filter by name using the following code:

RemoteRequirement[] req = connection.Requirement_Retrieve(new [] {new RemoteFilter {PropertyName = "Name", StringValue = "MyRequirement1"} }, 1, 10);

This works as long, as the requirement "MyRequirement1" does not have child requirements and I get an array that contains one element, as expected. 

However if it's not a leaf element, the RemoteFilter does not work and I get an empty array. How can I search for non-leaf elements?

Best regards,

Guenther