I have a problem that I can work around but now I need to explain it to a customer. Sometimes when I check a customer's files before printing the item will be one color and the color palette will show it as being another color or halftone of. Sometimes I can get it to go away through the appearance or the transparency palette. Sometimes the only way I can get it to work is to save the file down to Illustrator 8 or 9 and open it up in an older version. At that point both the color of the item and the value will match. Is this a bug in the program? It only happens in supplied files, and then only rarely. I've never known it to happen with halftones but in this case we were trying to match a previous print and the values differed about 10% between the programs.
I am using Illustrator 10 with the latest patches on MAC OS 9.2 on a 4 yr old G4 with 512MB RAM.
Our concern is how to check for it every time, and how to explain this to our customer.
Any help is appreciated.
Thanks,

An