Hi all,
This post is regarding using Designer Pro to edit print ready PDF's (with crop marks, colour bars etc) created using Photoshop and Illustrator.
I can do the edits, but if I try and export the file it corrupts (colour values change, some text changes col)

The files are supplied to me by a designer and sometimes I need to do urgent changes myself before going to print. I have unticked the 'add printers marks' box to avoid a double set of marks and colour bars and have the fonts installed too.
Does anyone have experience doing this? Any suggestions would be a great help!

Thank you in advance,
Tom