Often I find the same thing and need to refresh. However, in the "address" part of the toolbar (IE 4.0) it only shows
http://www.pprune.org for every page that is opened.
If I do refresh, it goes back to the main screen and I have to choose the forum, etc. Due to this I click on a post with the Shift key to bring it up in a new browser window and then refresh that one (since for some reason the new browser window has the full address of the post).