Can you build the dynamic contents for the List box provider in the getter for the bound managed bean?
In the Core Controls sample, there is a simple getter that is used by the List box page:
public ITableContentProvider getMeaContent() {
return m_meaContent;
}
It seems like you could check to see if the data was populated, and if not, invoke the webservice and generate the content provider.
#webMethods-BPMS#webMethods#MWS-CAF-Task-Engine