This is strange, to say the least. If I edit a message with dice rolls in it, the dice rolls change randomly. I can't figure out a way to change them to the original, and am lucky that I memorized the few dice rolls on sight before editing the post. 

The dice will

always reset once you edit the post. After the post is made and the dice are rolled, don’t go back and edit those posts, just add a new post afterwords.

That's odd though, since I've edited posts and none of my dice rolls have changed before.

Always happened to me.

Well, thanks for the tip. I'll make sure to remember it.

The dice don't always reroll when you edit a post. I'm not fully clear on the conditions, there have been a few threads about it in the past (I think it got brought up a couple times in the last big thread about the dice roller being broken), and an answer was never provided. Dice should remain as originally rolled, but are more likely to reroll if you're changing the text right around them. So if you post 'Krog attacks: 18 damage 9 and goes running for the door,' and later edit it to say 'Krog attacks: 18 damage 9 slashing and goes running for the door,' there's a chance the damage roll will be accidentally triggered into rerolling, but the attack roll wouldn't. Rolls followed by nothing but a carriage return are also likely to get rerolled if you try to insert another paragraph. If all your dice in a post are rerolling, regardless of where your edit was, that's definitely a bug.