opening pdf as 1.4 and doing a save as saves as 1.6 i want to stay as is, 4 other windows pcs doing the same activity stay as 1.4- the setting dlialogue all pc is grayed out

Acrobat x pro 10.1.1 all have the same versions and we all do the same task and only one of the pcs changes.

As simple as opening a 1.4 pdf and saving as pdf, definitely not using the optimize or reduce file size just as pdf- one of the pcs changes compatibility to 1.6