Pro Tools Le Problem, Getting a gray screen Options

[frame]

Hello everyone.
I have a G5, Dual 1.8, running Mac OS 10.3.5.
I'm using the MBox with Pro Tools LE 6.4.
I loaded up Pro Tools and hooked up the MBox. When I choose to start a new session, a dialog box opens so I can name the session. After I name it I choose save. Thats when the trouble starts. After I hit save, the box closes. Then this grey, opaque screen color scrolls down the desktop until it's filled up. (but I can see my desktop through it.) Then a solid grey square pops up and states shut down your computer or restart. This text is followed by a bunch of other languages that I'm sure say the same thing. I can restart and try it again, but it just happens again.

I found a post about repairing my permissions. I tried that but still get the same problem. Has anyone had this problem? If so what was your solution?

Thanks,
Frame