As sessions are clicked on the database browser top sessions grid, the current or previous SQL window on the bottom displays the most recently executed SQL statement of that session. When the SQL statement is displayed, the window is scrolled so that the first line of the SQL statement is always hidden. To view the first line, one must go to the display window and force the window to scroll up. This repeats with each selection of a session.
Waiting for fix to be released in a future version of Toad for Oracle.