I had some links to my site in comments using the old permalinks format and I decided to update them to the new format. When I tried however, I got a MySQL error. I looked on WordPress Support and found the issue but no one had provided a fix. Here’s one that worked for me.
Add the following line:
$content = $wpdb->escape($content);
right below line 694, which should be
$content = format_to_post($content);
in WordPress version 1.2 in wordpress/wp-admin/post.php
I posted a response there as well but wanted to help people to avoid the frustration of not being able to edit comments.