Hi Eric,
I searched for months to find a solution to this problem.
I am convinced the is some way to overcome it with code but I have not found it.
THE ONLY WAY that I have been able to consistently fix it is by doing the following.....
In IE Menu,
Go to Tools / Internet Options
In the Browsing History on the General Tab select Settings button.
In that dialog the is a radio button group called...
Check for newer versions of stored pages.
Make sure you check "Every time I visit the webpage"
You will find that it all works as expected then.
Let me know if you find a more elegant solution.
Cheers,
Mark