oh yeah - don't forget the thing about new password.
I'll have a look now.

problem fixed

I don't know if I am doing something wrong, but when I click on the Slinging.org logo to return to the home screen, it says I am signed out until I enter a post.

Sorry, CA, but you're misunderstanding.

This happens to me, as well. 

I can copy and paste the right address (http://slinging.org/forum/YaBB.pl) straight from the link you just posted or use the bookmark I have saved.  Either way, I always come in not logged in.  See image.








But if I click a link, in this case--Administrative, I'm automatically re-logged in with my saved details.  See image 2






All I did for these examples was to click my bookmark and then click "Administrative".  If I go back to the main forum now, I will stay logged in until the last forum tab is closed.  The only thing I can guess might be happening is that the forum is making the check for saved username/pass AFTER everything loads.  So we're being logged in, but we can't see it until we click another page.

Hope this helps.