Recent 500 Internal Server Error

Hello All,
Very recently, July 12 – 14, individual posts suddenly became un-reachable. The URI of http://howardparsons.info/some-post-or-other will return – after a bit of a wait – “500 Internal Server Error”. A visitor can go to http://howardparsons.info & then navigate around to find whatever they want but otherwise, the direct link to a post or page just won’t work.

Suspecting that it might be .htaccess, I stripped it down to the bare basics

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

and tried that with no change in the results.

I’m not sure what is going on here and would appreciate any and all help. If you want to test this for yourself, try http://howardparsons.info/thinking-of-buying-a-tablet/

Cheers!
Howard Parsons