Here is the debug report on the 'subscribe' problem:

[10-Feb-2009 09:38:43] PHP Warning: main(includes/templates/template_default/templates/tpl_subscribe_default.php) [<a href='function.main'>function.main</a>]: failed to open stream: No such file or directory in /home/sites/eminent.me.uk/public_html/includes/templates/Drop6/common/tpl_main_page.php on line 72
[10-Feb-2009 09:38:43] PHP Warning: main(includes/templates/template_default/templates/tpl_subscribe_default.php) [<a href='function.main'>function.main</a>]: failed to open stream: No such file or directory in /home/sites/eminent.me.uk/public_html/includes/templates/Drop6/common/tpl_main_page.php on line 72
[10-Feb-2009 09:38:43] PHP Warning: main(includes/templates/template_default/templates/tpl_subscribe_default.php) [<a href='function.main'>function.main</a>]: failed to open stream: No such file or directory in /home/sites/eminent.me.uk/public_html/includes/templates/Drop6/common/tpl_main_page.php on line 72
[10-Feb-2009 09:38:43] PHP Fatal error: main() [<a href='function.require'>function.require</a>]: Failed opening required 'includes/templates/template_default/templates/tpl_subscribe_default.php' (include_path='.:/usr/share/pear') in /home/sites/eminent.me.uk/public_html/includes/templates/Drop6/common/tpl_main_page.php on line 72
I'll take a further look to see what other problems it brings up.