Be careful when using the -gsize: option or parameters like clip in PostScript \specials that may be affected by magnification by magstep or -mag:.
Note that there may be problems when the size of the imported image is specified by using graphics.sty in the LaTex2e graphic package. So use graphicx.sty instead of that.
Even in PostScript files, some Encapsulated PostScript Files (EPSF) do not have proper format (such as %%BoundingBox: specifications at the beginning of the file).
In this case, the size specification in a PostScript \special does not work properly.