I have a galaxy S1 android os.
Also a gslate, its android also

Both of mine does it too sometimes. For me I gotta remember to close the keyboard after you pull it up before changing screens (player screens, auction terminal etc.) I usually have to tap the chat box and type something quick and then the enter key to clear the keyboard from the screen.

I have a habit of wanting to type something then changing my mind and deleting but just x'ing out, and the keyboard stays up every time. Annoying, but for me I type one letter, then press enter and it clears.