[eluser]mddd[/eluser]
That depends on the browser. If all caching in the browser is off, it will reload the page and show you the correct, logged-in page.
You could make the form page reload itself to be sure this doesn't happen and it will always show an up to date version.
Personally, I don't think there is a problem in this behaviour, as it is the browser doing it. Other site will function in this way too,
so users won't find it to be a problem, I would say.