I'm not sure if this is a cache issue, but it sure looks like something on the client side which is strange.  I have a VF page with a fairly complex layout for formatting purposes, that includes information from multiple related objects as well as two pageBlockTable tags.  It uses a custom controller to return various things.  This page allows the user to view the joined information and then "confirm" it for production.  The VF page is launched in a popup window from an scontrol page using a link like this:

window.open('/apex/orderConfirmation?scontrolCaching=1&id='+oliId+'&pid='+pid,'mywindow','width=1024,height=768,scrollbars=yes,menubar=yes,toolbar=yes');

The problem is, my IE7 users can run this VF page about 5 times and then the popup window will simply freeze and remain blank.  Closing IE7 and relaunching it solves the problem for another 5 times.  I'm looking at some IE7 settings but haven't solved it yet. FWIW I have run this confirmation page myself over 90 times in a row using Firefox and have not had the problem.  Do you think launching the VF page from an scontrol could cause this problem?

Mark