Adobe has disclosed in a recent TechNote that Photoshop CS5 can crash when doing a variety of tasks if you have certain MultiMaster fonts installed/activated. Unexpected quits can occur when clicking the mouse, using type, pressing tab, launching Photoshop, or just working on a file.
Apple revved their Mac Pros product line on August 9th. Of note from a troubleshooting perspective, these new Mac Pros boot into 64-bit (just like Xserves). This is the first desktop Mac Apple has released that by default boots into 64-bit mode, and therefore will not run 32-bit applications without restarting holding down the 3 and 2 keys.
Tip: To easily check if an Intel-based Mac is booted into 32-bit or 64-bit mode, click on the Software section in Apple System Profiler. There you will see “64-bit Kernel and Extensions” followed by either Yes or No.