T5: cannot use Grid's rowIndex in page class

[Geoff Callender]

Has anyone been able to use Grid's rowIndex parameter in their page  
class?
I see that it is supposed to be available from 5.0.15 ( https://issues.apache.org/jira/browse/TAPESTRY-1310 
 ) but I just cannot make it work.

From my template:
        <form t:type="form">
		<table t:type="grid" t:source="persons" t:row="person"  
t:rowindex="rowIndex">

and from my page class:

        private int _rowIndex;

        public int getRowIndex() {
		System.out.println(">>> getRowIndex(), _rowIndex = " + _rowIndex +  
")");
                return _rowIndex;
        }

        public void setRowIndex(int index) {
                System.out.println(">>> setRowIndex(" + index + ")");
                _rowIndex = index;
        }

but the getter and setter are never called - not during render and not  
during form submission.  Any ideas?

Thanks,

Geoff