Why does MacRumours log you off after a while?

There is a little check box that says "Remember me" or Remember password or whatever when you log in.

 

I always click the "Remember Me" check box. Did you try hitting the back button to save your post?

 

I believe the time limit is 15 minutes so either you can press the "Preview Post" button every once in a while or if you press the "remember me" check box when logging in you will not have this problem.

Also if you are writing a long post it is always sensible to keep a copy in the memory incase of any problems such as the one you descibe or browser crash etc.

 

I think Safari saves the text so if you log in from a different tab and click "Back," you'll have your post back. Somebody needs to test this though.

 

Spot on - click the "Remember Me" box and if you are planning on typing a thorough post it's always best to have a copy somewhere, even just on the clipboard (or whatever it's called in OS X ) in case the issue you described above happens, or something such as a browser crash.

 

MacRumors doesn't have any way of knowing whether you are typing in a long message, or have walked away from the machine for a few hours.

If it's a problem for you either compose your reply offline in a text editor, or make the first part of your reply, and then Edit that to flesh it out. You don't want to leave too much time before Editing though, as others will start replying to only the first part of your post.