Chat Problem

Occasionally, whenever I type in any of the Chat bars (all, trade, Alliance, guild, etc.), A large capital 'A' appears in a Square Box to the very right of the chat input area.

what does that mean? it doesnt do anything just sits there and be annoying.

Caps lock on? Well, by any chance are you running any type of accessibility software or keyboard utilities? Is the lettered box an overlay?

Screen shot possible?

Sometimes it does that if you are using an input language that doesn't use the typical English letters (for example, East Asian languages). The A shows that you are able to type using English letters despite choosing another input language (usually switched by hitting shift).