Using an older version of photoshop to print the targets isn't a total solution, either. In my case, I have CS3, not CS4, and while Adobe doesn't bless "compatibility" for CS3 with 10.6, all of the CS3 programs appears to work OK in Snow Leopard. However, while CS3 appears to run correctly in OS10.6, I can say with certainty (and two painful days of testing) that PSCS3 and the Epson 3880 driver just don't talk to each other under OSX 10.6 the same way they do when printing to identical driver under OSX 10.5 (The same Epson driver is recommended for both 10.5 and 10.6).
One can use either the "Photoshop manages colors" with the No color adjust method, or even use the null transform technique, and the PM5 TC918 target prints well on the OS10.5 machine but differently under 10.6. The printed targets from both systems look like plausible "no color adjust" results yet they differ by a max delta E = 26. The tip off that something was wrong with the 10.6 version came to light because the resulting profile had poor quality (hooking in the blues) and usually making a custom profile for an Epson paper on an Epson printer with PM5 profiling software is a no-brainer.
To summarize, the printed targets from both systems both looked like a plausible "no color adjust" output, but the profile made with target data and same settings under 10.5 = good, profile made with same settings under 10.6 = bad. Ironically, printing the target out of InDesignCS3 on 10.6 using a null transform method matched the CS3/10.5 NCA method output perfectly (within experimental error).
So, my conclusion is that just "keeping an older copy" of photoshop around for target generation isn't the answer, either. Upgrade hell is alive and well!