this update only applies to those two users experiencing login and staying logged in problems.
The issue is caused by a very technical problem which I can work on, but it may take a while as I need to aquaint myself with a whole new area of mysql.
In the meantime...
if you get logged out and returned to Guest status, please try hitting the HOME button and see if this logs you back in.
If not, please either email with a detailed account of what did happen, or if you can, post details here.
For once it seems the forum software is in advance of the host's server software, and this is where the problem lies.
I am working on it.