You have to add no-cache meta tags, three to work in all browsers.
Code:
For IE:
<meta http-equiv="Pragma" content="no-cache">
For IE 5:
<meta http-equiv="Expires" content="-1">
I believe for non HTTP/1.1 compliant servers:
<meta http-equiv="CACHE-CONTROL" content="NO-CACHE">
If you use AJAX to update your pages, send a random number as a parameter to ensure the page is not cached.
Try clearing your .htaccess file to see if that helps with the url problem. That must be the servers doing.
Add all this code to your page and you should be fine