[TWTCommish]

Yes, just recently. If you're using both an embedded external image AND an uploaded signature image in signatures, find the "Remove external link on postbit signature" plugin and change its location from "postbit_display_start" to "postbit_display_complete" and populate it with the following code:

global $vbulletin;
if (!$vbulletin->options['external_verify_sigs']) {
  $this->post[signature] = str_replace($vbulletin->options['bburl'].'/externalredirect.php?url=', '', $this->post[signature]);
}

You might have to empty your signature cache under Maintenance -> Update Counters, as well. Let me know if this works for you.

Regarding the 500 error; I'm afraid I don't quite understand that last part. Could you rephrase?