It is the Input Language Indicator. You can activate it by pressing Alt + Enter ..
Menu - options - Language and Text Input - Lanuguage ID - set this to "Hide" (Im running OS 5.0, therefore not sure whether you have these options or not)
Checkout the settings under Menu - options - localisation - you will see the input language settings here... There is an option "Notify Me" - set this to NO and see whether it solves the issue (not sure abt this though) ....
Try asking the TH Council. I usually ignore mine because all it does is tell you. If you are using the caps feature or if you are using the number lock feature. Guess it is the same as using shift and the alt button.
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