I'm not so sure that the problem is the different browsers. Because the same just happened to me, using my normal browswer only, not doing anything differently than other times, and it stole my PoE anyway.
I answered correctly, even got the message "Your answer was correct and you earned 5 pieces of eight!" but didn't get the 5 PoE.
I think abandonia just fucks up from time to time without any obvious reason. Dang.
So, congratulations, you are ahead of me again now
