intermittent session loss

Hi, I think I may have made some headway with my server problems. I loaded the site onto another account within the same machine, and I can't seem to replicate the "document contained no data" error at all. BUT I did notice that once I login (it says "you are logged in as justin" across the top of the screen), if I refresh the same page a few times, it will MOSTLY say "you are logged in as..." but OCCASIONALLY it says "click here to login"... The server does use trans-sid, but in my case, it's using cookies... the session doesn't get LOST (because it's "back" next time I refresh), but I do appear to be "logged out" until I refresh again. VERY strange. To investigate further, I turned off cookies, and tried again... after 5 or so refreshes, I lost the session ID out of the URL. Whilst I can't repeat the problem on the original account, I have a feeling these two issues are related. What's likely to cause this? Here's the Session section of phpinfo(): -- Session Support enabled Directive Local Value Master Value session.auto_start Off Off session.cache_expire 180 180 session.cache_limiter nocache nocache session.cookie_domain no value no value session.cookie_lifetime 0 0 session.cookie_path / / session.cookie_secure Off Off session.entropy_file /dev/urandom /dev/urandom session.entropy_length 256 256 session.gc_maxlifetime 900 900 session.gc_probability 1 1 session.name PHPSID PHPSID session.referer_check no value no value session.save_handler mm mm session.save_path /tmp /tmp session.serialize_handler php php session.use_cookies On On session.use_trans_sid 1 1 -- My LAN server's values (not compiled with trans-sid) are: -- Session Support enabled Directive Local Value Master Value session.auto_start Off Off session.cache_expire 180 180 session.cache_limiter nocache nocache session.cookie_domain no value no value session.cookie_lifetime 0 0 session.cookie_path / / session.cookie_secure Off Off session.entropy_file no value no value session.entropy_length 0 0 session.gc_maxlifetime 1440 1440 session.gc_probability 1 1 session.name PHPSESSID PHPSESSID session.referer_check no value no value session.save_handler files files session.save_path /tmp /tmp session.serialize_handler php php session.use_cookies On On -- Biggest difference I can see (not that I really know what I'm looking for) is that locally, the save_handler is 'mm' (memory?), and on the server, it's files. And the entropy stuff, which I don't understand :) So, what could cause the session to drop (then kick back in again) by simply refreshing the page a few times? Many thanks in advance, Justin French