Thanks for your feedback. This is the first I’ve heard of this issue and I’d really like to help resolve it. Most likely there was some sort of fatal error triggered on the update of the post (which triggers a recalculation of the related posts).
Do you have a PHP error log on your server? Also, if you turn WP_DEBUG on, it may print some errors instead of giving you a completely blank screen. I would really appreciate it if you could try to reproduce this issue and give me more information.