Undo causing Crash
 

I got Maya 2009 running on a Mac Pro Quad with 10 Gb of Memory and a NVIDIA GeForce 8800 GT and a Dongle for Licensing, Randomly when pressing the Undo button (Cmd Z) on the keyboard which is wired usb it causes Maya to just quit and Vanish. It does not stall or anything.? Having not saved I have just lost my work again.

Here is the contents of the Log File for the 2 Crashes

22/11/2008 17:31:30 [0x0-0x6b06b].com.alias.Maya.2009[812] mental ray for Maya 10.0
22/11/2008 17:31:30 [0x0-0x6b06b].com.alias.Maya.2009[812] mental ray: version 3.7.1.26, Jul 30 2008, revision 26576
22/11/2008 17:43:19 [0x0-0x6b06b].com.alias.Maya.2009[812] Fatal Error. Attempting to save in /var/folders/BM/BMfvHvFoG8CHZIUiesPQHE+++TI/-Tmp-/MyNameHere.20081122.1743.ma
22/11/2008 17:43:31 [0x0-0x6e06e].com.alias.Maya.2009[829] mental ray for Maya 10.0
22/11/2008 17:43:31 [0x0-0x6e06e].com.alias.Maya.2009[829] mental ray: version 3.7.1.26, Jul 30 2008, revision 26576
22/11/2008 18:41:58 [0x0-0x15015].com.apple.Safari[166] Debugger() was called!
22/11/2008 23:18:30 [0x0-0x6e06e].com.alias.Maya.2009[829] Fatal Error. Attempting to save in /var/folders/BM/BMfvHvFoG8CHZIUiesPQHE+++TI/-Tmp-/MyNameHere.20081122.2318.ma