>lncomplete=4
>do while readystate<>lncomplete
>enddo

Well, it was even easier than that but you gave me the clue to the solution. I had a form Refresh() call right after the Navigate2 and this seemed to be causing the problem. I still don't know why it worked on one machine and not the other, but moving the Refresh() to the browser DocumentComplete event made the problem go away.