Steps to reproduce the bug: Fill up the chat history window enough so it can be vertically scrolled, move the scrollbar position up, and click in the chat text-entry field.
Observed results: The chat history scrollbar position resets to the bottom instead of remaining where it was.
Expected results: The chat history scrollbar position should remain where it is until explicitly reset by the user. A new text indicator (static down arrow "v", for example) could be added.