Thanks for the help kev.
Actually I think this is a bug: I googled 'gzip php5 phpbb' looking for some help, and found this reference to previous problems with these three under the changelog for ver 2.0.3
Fixed some problems with gzip in combination with newer PHP versions and Mozilla
So I gave IE a go and it worked, but still gave some errors at the top of the page.
I'll see if I can submit the bug - I thought that it might have been fixed in an update so I went to the server tab in ACP. but all I get on that page is
in a red box.
How do I fix this? I have searched on found nada...