Thanks, its a 4 layer board....and i wonder if i do "EXPORT DXF" for ech project, and do this with only the 4 copper layers selected, then it will give me a dxf file which corresponds exactly to the exact copper shapes of layers 1,2,3,4...then i can convert the dxf to a txt file.....then do the same as this for the other project.......then use NOTEPAD++ to compare those 2 text files....if they are the same, then i can be garanteed that the copper shapes on all layers are the same for each project.
Also, doing the same thing with the PCB netlist file, and the schem netlist file...and comparing across.......if these TXT files are all the same between the projects, then surely those 2 pcbs are pretty darn sure to be the same?