I just had an interesting revelation in a lab. The operator let me have a look at the edit software that queues the files ready to print, it also has an auto correct function. While I was looking at my already corrected in Lightroom files going through I noticed that it was auto correcting them and doing a mighty bad job, blown highlights, blocked shadows, colour changes, nightmare. I asked the tech what was going on and he said that in his experience that the files that were from Lightroom, Canon DPP, or anything other than Photoshop, they were auto corrected and IT CAN"T BE TURNED OFF, EVEN WHEN IT WAS UN-TICKED IN THE PREFERENCES. As I was getting 200 9x6 inch prints and it was 2/3rds of the way through I asked him to stop. Then we experimented and it appears that Photoshop saves the file with an icon and the others don't, we couldn't see any other obvious differences so the Frontier printer must make adjustment to files without an icon. Bizarre but true. I am going to go to a lab with a Noritsu printer and I'll take two identical files, one saved in Photoshop and the other from Lightroom and see if it does the same thing. You have been warned. If any one has any other explanation I would be glad to hear from you.