I am really hoping someone will have some insight into this.
What I am experiencing seems only to occur in firefox and safari. I have not tested Opera but have tested IE and Chrome which I have never been able to replicate the issue.
What is happening is on a page that uses sessions (PHPSESSID) to identify a user either someone who is logged in or just someone adding an item to a shopping cart, when they click on a page using Session information the page is so slow to load that it can take 5 minutes to load. The page does eventually load correctly and the session data is still in tack (not removed or deleted). Now the strange thing is while this slow loading page is occurring if I then click on another page that does not use SESSION information the page loads quickly and correctly but if I then click on a different page that does use SESSION information the same slow loading/hanging occurs and will continue to occur on all pages I try to load that use session information until the 5 minute hanging is over.
Now to make things stranger this does not happen all the time, only occasional and not on the same pages, but it only occurs on pages that use SESSION information and only occurs in firefox and safari which seems strange to me as Sessions are server side with the exception of the PHPSESSID cookie which does remains in tack during this slow loading/hanging pages.
I have been in contact with my host and asked them to test it. They have not been able to replicate it and there are no warning or alerts in the logs. I have also had other people test it, it happens very rarely but seems to be increasing in frequency.
I have two main questions. 1) does anyone have any ideas as to why this would occur and why it seems to be browser specific. Could html validation make any difference? My pages are running under DTD XHTML 1.0 Strict which I will need to change to Transitional to validate. I did test this thinking it could be the answer and was hopeful. When I validated a page this problem was occurring on I though I had solved it but eventually the hanging did occur. But I have not given up hope that validating would help. What else could cause this strange thing?
Question 2) is the any tool that could test what is happening when this occurs. Could firebug give me some clue and if so what part. Is there any other browser tool or software that can help me analyse this when it occurs? I use a Mac.
Many thanks as always for your help