RMagick convert ps to pdf

Question

When I convert a ps file to pdf, it works fine on the local machine, but on the production server, it adds margin to the page, as if I selected Scale to Fit instead of Scale: 100% from the Mac OSX Preview print settings. How do i prevent this? Currently, I'm doing:

Magick::ImageList::new('cool.ps').write('cool.pdf') # only works on local machine

Thanks!

Matt