Take a look at the CPCurrent() help topic. If one of the developers has CODEPAGE set in their configuration file (CODEPAGE = 0|1252|AUTO) and it is different than the other developers, it will overwrite the codepage of any files they open.

I was suggesting in my previous post that you could force the CODEPAGE of the PJX file to 1252 or 0 by running CPConvert() or CPZero.prg, if your developers aren't all on the same page - so to speak.