Lost back-forward arrows with Safari 2.01

A couple of weeks ago, the back/forward arrow pair in my copy of Safari 2.01 suddenly disappeared. The home icon shifted to the left to replace the arrow pair. The arrows still appear in Safari 1.3. However, if I update a copy of 1.3 to 2.01 with a freshly downloaded updater, the arrows disappear again. It doesn't matter on which volume Safari resides as long as I use my Tiger volume to boot. Does anyone know how to fix this?