When you're trying to type something, the cursor highlites the chat designator eg: !/+/@/" so if you're not attentive, if you're trying to chat for example in Clan channel, you click it, then use the left key to unseleft the '@' char and then type.
Otherwise the '@' will be erased and you'll send your outburst in the local chat.
Is that a bug or how things work now? If it's the later, it sucks.