>For some reason, the board shop moves tracks around. There is no logic to the changes and I can think of no justifiable reason to do this without the customer's permission, but it is especially concerning when your products carry UL/CSA agency approvals.
Sounds like you need a new board shop. That's what I once told our drafting department when I asked for controlled impedance traces and they told me the pcb vendor would just laugh at this request.
Heard a tale several years back about a board shop that would enlarge clearances around vias through ground planes, probably so their process could be cheaper. This cut the plane wide open and introduced slots and no-connects.
@Antedeluvian: The conversation would go like this: I would ask the interpreter here in Toronto to ask the technician in China if a particular LED on a relay was on. This was communicated via a relatively lengthy conversation...
This reminds me of a television documentary I saw more than 20 years ago in the UK. There was an English reporter/investigator questioning a Japanese (or Taiwanese or Korean -- I forget) businessman -- they were standing in some industrial setting like a shipyard. All of the questions and answers went through a translator.
At one point the interviewer said something like "So, are the reports true that you've been syphoning off some of your company's money into your personal accounts?"
After that was translated, the businessman went into a 5-minute diatribe -- jumping up and down -- waving his arms around -- shouting -- bright red in the face -- the Full Monty. Eventually he ground to a halt .. the interpreter turned round to the reporter and said "No." LOL
Aubrey, you say: "and obviously the experience is profitable for us". This is the fuel that keeps things like those happening. So, I am affraid to say, somehow you (or your Company) deserve the pain and stress that all of this brings. So, with all respect, please enjoy!