Try to click View->Toolbars->Math Panels!
HTH EkkehartAll told, I'm ok with replacing the math panel with menu entries, drop down lists, tool buttons, whatever. In 1.5.0beta3, I can find how to insert delimiters (and a variety of other stuff), but where did the arrows and other symbols go? Or are we now required to remember the LaTeX commands for them? (In general, the word "remember" is anathema to me.)
/Paul