IE6 Checkbox selection model issue

I have added checkbox selection model to grid panel. It works fine in IE8 and Firefox.

In IE6 data in the grid is not rendred if the grid has 10 records only few records are displayed . The web page throws an error saying col 0 is null or NAN where column 0 is checkbox for the grid panel.

In ext-all-debug.js at line 60814 throws an error saying it is null

getCell : function(row, col){
    return this开发者_如何学编程.getRow(row).getElementsByTagName('td')[col];
},

Can you please help me with this issue

it was a data issue..it is working fine now..