Just for information, in case others ever get this problem.
I was having a problem synchronising my forums, as it kept giving me the message: Fatal error: Maximum execution time of 30 seconds exceeded in.....
The problem was I have a lot of categories and subforums.
I solved the problem by adding this line "php_value max_execution_time 60" in the .htaccess file in the root directory of my site. Amend the value of 60 to whatever is necessary to get the job done.