After catching a Ether wind while i was wandering in the wilderness, i got "gravity" disease, leading my character to be overweighted.
Very annoying, and as i used already the cure corruption potion given in the message to the king quest, i went to Palmia to play Blackjack, as from the wiki, you need to win 4 times in a row to get such a potion again.
And wow, i must be unlucky or something, but the amount of time the bank managed to reach a 21 and breaking my win streaks was rather amazing.
So at some point i went to read a bit more spoiler and noticing the hint to potion of hero that increase dexterity : you can cheat in those blackjack games with your chance to avoid detection being dependant on dexterity. That's great that i had a collection of unused hero potion then.
And i noticed that the cheating ability in Blackjack was actually not badly implemented, because it's not an auto win, but more of a card re-roll, meaning that if you're really really unlucky, cheating will take time.
Finally after 3 streaks of win, i managed to use the cheating ability and re-roll a card that would have led the bank to break my streak if not changed.
Ah no more gravity disease !