Either the inset is incorrect on screen or when printing, but the amount demonstrably differs when printing. In the initial sample it had the effect of reversing the colors.

Create a new document
Type 'TESTING' in Times New Roman
set as bold
resize to about 121 points to better see the effect
convert to text to path
set color gradient (e.g., blue to green) using "shape"
set taper to Sine, inset 0.1"

Observe on screen, this is blue edge with blue centers and gradient to green inbetween.

Print, this is green edge with green centers and gradient to blue in between

(okay, the strokes are thick enough at that size to pass to whatever the transition color is in the middle)

If the inset is left at the default 0.5" the same reversal occurs, just with a different "length"

This is easier to reproduce. Just draw a box and set shape fill with Sine taper.

Any chance you have an older version (old Windows, something pre Linux when the display/output code all changed) installed which the screen and output coincide? I can fix either one but I am unsure which one is correct!

[Status updated to 'Assigned' on Sat, 05 Jan 2008 14:07:01 -0500]

fixed in postscript.prolog 1.5 (25.5.0

[Status updated to 'Fixed in ' on Mon, 26 May 2008 18:52:54 -0400]