The suggestion would be in Reginald's dialogue after giving him a tip. I was thinking you could have a bit of an extra dialogue line, or just an option where you go "It's called a tip, you ingrate!"
The bug report though, I'm not sure how many people came across this so you can ignore it. In the middle of a dialogue with Arhu, perhaps even with the trade window open, I load to another saved game. So when I talk to someone else, the dialogue window becomes merged with what was supposed to be Arhu's.
