Illustrator CS5 vs CS4 EPS printout Problem

[drummerpaco]

Good Afternoon.

I have noticed when I print the Illustrator EPS file that saved in CS5, it came somewhat different then customer provided printed out. So I used another computer to use CS4 and then the print out came out same as customer provided printed out. It is exactly same file but different output. the CMYK image looks exactly same in CS5 and CS4 EPS, however it is Pantone color that has overprint + Transparency.

the file include;
PSD and Tiff linked file
- PSD has two pantone channel (CMYK+2 PMS)
- tiff file (transparency background) is layered on top of PSD file

We have ORIS Color tuner Web + Epson 7900 with onboard Spectroproofer

It seems like assigned profile or different pantone read from CS4 and CS5.
Is anybody can help???

[Glenn McDowall]

you need to resolve any color space / pantone conversions before you flatten the transparency. Saving as EPS will flatten. I seem to remember overprint+transparency (cmyk+cmyk) gets worked out the same as working out what the overprint color (Result 1) would be then applying the transparency effect of "Result 1" acting on the original lower objects.

[drummerpaco]

well, I have tried both without embedded image or with embedding image as well.
It seem it act both as same result. Flatten image will diregard the color profile that Original image has which we set up as GRACoL 2006 color space.

I tried bothe CS5 and CS4 to have same color setting. Still different result.

About the pantone conversions that you were mentioning, what exactly are you referring to?
Should we have to have plug-in setup for Pantone conversion?