I tried to log out of my Wordpress Admin by using the following link (I've removed the _wpnonce)
http://shkspr.mobi/blog/wp-login.php?action=logout&_wpnonce=

This generated the following error.

Parse error: syntax error, unexpected '(', expecting ')' in /home/shksprmo/public_html/blog/wp-content/plugins/wordpress-mobile-pack/plugins/wpmp_switcher/pages/mobile_login.php on line 28

Warning: array_merge() [function.array-merge]: Argument #1 is not an array in /home/shksprmo/public_html/blog/wp-content/plugins/wordpress-mobile-pack/plugins/wpmp_mpexo/wpmp_mpexo.php on line 446

Warning: array_merge() [function.array-merge]: Argument #2 is not an array in /home/shksprmo/public_html/blog/wp-content/plugins/wordpress-mobile-pack/plugins/wpmp_mpexo/wpmp_mpexo.php on line 446

I had previously enabled mpexo on my blog.

The error occurs here

function wpmp_mpexo_send_payload() {
  global $wpmp_mpexo_payload;
  global $wpmp_mpexo_payload_forced;
  if (get_option('wpmp_mpexo_enabled_beta')!='true') {
    $wpmp_mpexo_payload = $wpmp_mpexo_payload_forced;
  } else {
//line 446
    $wpmp_mpexo_payload = array_merge($wpmp_mpexo_payload, $wpmp_mpexo_payload_forced);
  }

As you can see, neither $wpmp_mpexo_payload nor $wpmp_mpexo_payload_forced are initialised.

I've checked and, despite clicking on logout - I'm still logged in.