Sometimes I'm logged in and hit a page or try to do something that C5 doesn't like and I'm shown the login screen. But I'm not actually logged out -- it's only if I keep trying to hit that page (and if you try to log in then it's just sending you back to that same page that it wasn't allowing you to see so it's showing you the login page again). Meaning that the user isn't actually logged out -- for example, instead of trying to log in from that screen, just go back to the site home page (type the URL into the browser's address bar, for example) -- you will probably still actually be logged in.

This of course doesn't solve your problem, but maybe helps narrow it down a little? I'm guessing it certainly has something to do with the way permissions are set on the various pages.

It was the permissions of the page from which I was adding a new page. When write permission is granted it works but I dont really want the user to be able to edit the page, just for them to be able to create one.

Is there any way to stop this , also is it possible to create a button "add Page" to the Main area instead of at the top of the page.

I believe if you turn on advanced permissions, you can do more fine-grained things like this. Search the docs and the forums about this, I haven't used it myself so I unfortunately can't provide any more specific details.