Windows Suddenly Gone in Motion

I've got a Mac Pro 2 X 2.66 GHz Dual-Core Intel Xeon, 5 GB 667 MHz DDR2 FB-Dimm Ram, Mac OS X 10.4.11, QT 7.3, Motion 3.0.2.

Everything has been running fine except suddenly, my window on the left with Library, Inspector, and File Browser won't appear when I open projects. When I try to hit keyboard shortcuts to bring up the windows, I see the menu indicate at the top of the screen like it's trying to pull something up, but the side of the screen where a window should appear stays empty. I've tried restarting my computer or opening different projects. All the other shortucts to open the layers tab, canvas, etc., work fine. Just not the windows with those three areas I indicated above.

I've tried different keyboard layouts. Nothing seems to bring up those windows.

Anyone ever encountered this before? Weird...

Thanks,

John