Peter,
>Your code looks very similar to mine and yes NODEFAULT is there
Is it a file on the local harddrive or on a network resource? If it's network you might need a delay until it flushes before you ask the browser to load it.
I'm not sure what else can be going wrong. The technique does indeed work quite well I use it to display a column formatted result that lets the user select multiple rows of a single column value for a copy/paste operation.
Update: We do have a difference.. I call the Navigate() method and you are using Navigate2() you might try switching it to see if that solves the problem.