Resolved: My posts are being sent twice, and I don't know why

Straight to the point, lately, I've been posting a lot of pictures in a certain ROM Hack's thread.
The problem is that when I post them, even though I click only once the button that says "Post Quick Reply", the post is being sent twice, and I always have the stay alert and remove one of them in order to avoid possible infractions.

Now, I know for a fact that my ISP nor my connection itself are the problems because it's only happening here, in PokeCommunity. So, is there a way to fix it?
I'm using Mozilla Firefox v55.0.3 (64 Bits), thanks in advance for reading.

It's my understanding that this is a problem with threads that are very long in posts and pages. Are you experiencing this in ALL threads?

EvilChameleon said:

It's my understanding that this is a problem with threads that are very long in posts and pages. Are you experiencing this in ALL threads?

Click to expand...

I'm not really active in terms of posting outside of that thread, so I'd say that's definitely the problem.
The thread has 451 Pages, so yeah.. I guess it's normal behavior. Thanks for the reply :)

If you're talking about Adventure Red, that thread has had double posts for ages now. It happens when a thread gets particularly large but now I'm not there to deal with them and Christos is slacking :P.

Just so you know, this problem can mostly be avoided by using Advanced Reply in lieu of Quick Reply as well. :]