Remember this guy? http://forum.square-enix.com/ffxiv/t...-t-see-my-chat
He apparently got it resolved, asking for "someone to look into my account to see if there are any chat restrictions" and having a GM flip a switch or two. People were saying he was flagged as a trial/restricted account.
Same thing's happening here. I can send messages, but unless they're /say, /shout, or /party in Duty Finder, nobody sees them. Posting here after being redirected from an e-mail ticket. This is a 100% frequency problem that only occurs on my Sargatanas character, and it's been around for at least a month and a half, but not the entire lifetime of my account. I would've reported it sooner, but when leveling solo it wasn't really a problem. At 50 and as a member of free companies and linkshells is a different story.

(And for the record I can verify that people aren't just ignoring me, I've had friends confirm it from outside the game or with /say.)