This is my table view delegate:
- (void)tableView:(NSTableView *)tableView willDisplayCell:(id)aCell forTableColumn:(NSTableColumn *)tableColumn row:(int)row
{
    id theRecord;
    NSMutableString *gid;
    theRecord = [tableDataSource objectAtIndex:row];
    gid = [theRecord objectForKey:@"gid"];
    if (([gid intValue] % 2) != 0)
    {
        [aCell setDrawsBackground: YES];
        [aCell setBackgroundColor: [NSColor colorWithCalibratedRed: 237.0 / 255.0
                                                             green: 243.0 / 255.0
                                                              blue: 254.0 / 255.0
                                                             alpha: 1.0]];
    }
    else
    {
        [aCell setDrawsBackground: NO];
    }
}
It works fine to display normal cell but the tableview get frozen after I add a cell with NSButtonCell type (for checkbox). How to fix it ?
Any help would be appreciated.