sortProperty not working for treetable column

Hi All,

I tried creating a treetable(sap.ui.table.TreeTable) with few columns(sap.ui.table.Column). It works fine normally.When i add a column with sortProperty="name", and run it, click on the column and choose sort Ascending or Descending, it gives an error "[object object] has no method 'sort' "

When i try adding the sortProperty="name" for a column to a normal table(sap.ui.table.Table), it works fine! The problem occurs only when using TreeTable.

You can check the code sample at http://veui5infra.dhcp.wdf.sap.corp:8080/snippix/#31040

Can anyone please help me out with this issue. Im not able to figure out why is it not working with TreeTable!

Thanks,

Vinay