There appears to be a new bug that may obscure this one.  When I follow
the example instructions: 

"- in 3.6 image, open a new StackMorph
- add a TextMorph to the first page
- set text alignment to centered
- from the Stack's red "menu" halo button, select "copy & print" -> 
"print Postscript to file" and accept defaults.
- a walkback appears: "PostscriptCharacterScanner doesNotUnderstand: 
#setAlignment:?""

in 5923 I get a different bug which appears to be related to a change in
update 5660 by Ned.  For some reason Ned's code attempts to
'DSCPostscriptCanvas>>drawPage:' on a collection of pages as returned
from 'StackMorph>>pages'.  fullDraw: doesn't like that.

Whether the old bug is still their and I'm just not getting far enough
to see it, I don't know.

Ken