I have NoScript, and AdblockPlus, on Firefox.
But that's not it.
Thing is, I'm pretty sure (like, around 85%) that I had included the OP's name in the quote. Since the only way I can work out how to do this, is manually, it makes the procedure slightly more memorable than just hitting "quote/reply" - or variations thereof used by other forum software.
But it could be a bit of creeping forgetfulness, I guess.