I'm obviously not Todd, but I ran the updater without incident on my tower and laptop (both on 10.6.8). I suspect your problem isn't Adobe-related, but rather Mac-related.
I suggest routine maintenance, then try again. Repair Permissions. Run Disk Warrior. Zap the PRAM occasionally (hold p,r, option and command on boot, and wait for two or three chimes before letting go), and try booting in Safe Mode (hold shift on boot) before running the updater. And/or, try creating a new user with Admin privileges, and try again.
You could also consider un- and re-installing CS6.
I don't have any expertise or knowledge about the installer or the CSXS updater. The best that I can do is recommend this forum, which is where the people who know the installers and updaters are active:
Also, Jim's advice about uninstalling and doing a clean re-installation is sound advice.