To use stored procedures with visualweb, instead of using the rowset, in a Session or Request bean, write your JDBC code to execute the stored procedure then store the result in a Java Array.
Next, from the Palette, drag and drop an ObjectListDataProvider (OLDP) onto a new page in the visual Designer. Next, from the Outline, expand the nodes until you see the OLDP. Select the OLDP and in the property sheet assign the value of the array property to the Java Array that contains the result of the stored procedure.
We'll try to have an article describing this, soon