Yeah. I get: "Could not complete your request because of a program error" … I thought maybe it was a memory glitch … although I have 1.5G … so I restarted but still same error.
Try trashing your Photoshop preferences first, see it that helps. If it doesn’t, quit Photoshop and delete prefs again, then run Repair Permissions (Apple’s Disk Utility), then re-install Photoshop, and finally Repair Permissions again.