DPI Question
I don't think the .prj file is producing different results. If you render a
single frame of the same scene from the same .prj file on two different
computers, and the load the two images into the _same_ image-processing
software, you should get the same resolution for both images. (To troubleshot
[troubleshoot] this, you need to narrow the process down to a single variable.)
If, given this process, the two images are reported to have different
resolutions, then you're not going through the exact same steps when rendering
the images on the two different machines. For example, one operator might be
rendering from the 3D Editor, and another from the Keyframer.
We'd be interested in hearing from you when you track down the solution to this
puzzle.
– J