Why are apostrophes turning to question marks

[Stephen]

I thought it was just me but I guess not

[Trip McNeely]

They want you to make sure you’re grammer is rite.

[AnthonyS]

Y?all just can?t have nice things anymore.

[4bangen]

I just read that message in my thread and the question marks drove me nuts.

[Captain Chaos]

I almost went back to edit it, but then realized I didn't know how to fix it since there wasn't anything wrong in the first place. Weird.

[bird_dog0347]

I'm guessing it's a bug in the vBulletin software this forum uses.