Drupal 500 Internal Server Error on shared hosting

Was getting irregular "500 Internal Server Error" pages on a new Drupal 6 install, running on shared hosting.

After some research it appears that the hosting company is running php5 as CGI which does not follow the PHP directives set in Drupal's .htaccess file:

# PHP 4, Apache 1.
<IfModule mod_php4.c>
  php_value magic_quotes_gpc                0
  php_value register_globals                0
  php_value session.auto_start              0
  php_value mbstring.http_input             pass
  php_value mbstring.http_output            pass
  php_value mbstring.encoding_translation   0
</IfModule>

# PHP 4, Apache 2.
<IfModule sapi_apache2.c>
  php_value magic_quotes_gpc                0
  php_value register_globals                0
  php_value session.auto_start              0
  php_value mbstring.http_input             pass
  php_value mbstring.http_output            pass
  php_value mbstring.encoding_translation   0
</IfModule>

# PHP 5, Apache 1 and 2.
<IfModule mod_php5.c>
  php_value magic_quotes_gpc                0
  php_value register_globals                0
  php_value session.auto_start              0
  php_value mbstring.http_input             pass
  php_value mbstring.http_output            pass
  php_value mbstring.encoding_translation   0
</IfModule>

This post suggests commenting out these PHP specific settings, and adding the following to your php.ini (if you have access to it - some hosting companies don't allow this, although there are workarounds):

magic_quotes_gpc                0
register_globals                0
session.auto_start              0
mbstring.http_input             pass
mbstring.http_output            pass
mbstring.encoding_translation   0

This seems to work - I'll update in the comments if I run into this issue again.