Address is http://www.biginjapan.co
I’ll go back to my simple things now!
The main and cache directory both have CHMOD permissions of 755.
Well I’ve found out the Global Translator plugin being enabled is causing the problem. Now to find out why!
Downloaded a fresh copy of WordPress 3.0.1, uploaded the wp-admin folder (after backing up the current one). Tried editing a post and still got the same 500 error, the server error log giving me:
[Mon Aug 16 03:27:38 2010] [error] [client ***.***.***.***] Premature end of script headers: php.cgi, referer: http://soldave.ismysite.co.uk/biginjapan/wp-admin/post.php?post=1247&action=edit