Well there are only 11 posts in that thread and 4 of them are Shuffs, it doesn't look to be too wide spread a problem. By that I mean it seems to me it would be more likely a problem with your computer/controls than it would be with the game. Out of 7000 people flying, even if 10 have this problem it's still only .07 % right? If it was a game issue I would think you'd see a lot more complaints especially if this has been a problem since a couple of updates ago.
How old is your stick? How long do you play these others games as compared to AH? Does the hat switch get the same work out and chance to screw up in those other games as it does in AH? Seeing as you have tried your stick on another computer and the problem has followed you I think it was the stick first thing. Hardware goes long before software in pretty much any application you can look at.
Like I posted in that other thread, I DID have a problem, but after changing my switch I have no longer had a problem.