Odd behaviour

[#1]

The last couple of days I have noticed odd things on my forum, for a start I saw someone registering an account and I think it was the same person, and yet in the end there was no new member showing up, and then today a guest was posting in my Q&A forum (guests only allowed to post in the Q&A forum for now) and yet after a while no post appeared there.
I am puzzled by this and not sure if my forum is working ok for guests, anyone else got or is familiar with phpbb3?
I don't understand to well, so if anyone knows or can help explain this please don't talk technical to me.......thanks 
Maybe its a case of the person changing their mind, but it seems unlikely given that they had tried twice or more and nothing happens.
I have set my permissions up ok and for how I want them, but I am just stumped by this, and as I would like members, I hate the thought that they are finding it difficult to post or sign up, and no knowing what to do about it, is for me frustrating 
Jekyll 

[#2]

Try this,
Logout so that you become classed as a Guest,
stay as a Guest try creating a post yourself in your Q&A Board.
If it doesn't work there will either be:
An Error or
No page displayed or
The Post wont have inserted
If there is an error you should be able to punch it in to a Search on the Documentation,
If nothing is displayed there is problem with the Script(s),
If no post was inserted then it's also a problem with either Script(s) or Board Permissions.
See what that brings up
Jim,

[#3]

Ok done that and the post showed up fine as a guest
Maybe I just have gremlins at work on my site 
Thanks anyway