Non-printing PS files?

[Walsh]

After several unsuccessful attempts to print a PS file of unknown origin
from a Sun to an Apple LaserWriter I changed the first line in the file
from

%!PS-Adobe-1.0

   to

%!

and the file printed just fine.

I am a new PS user; hovever, the strange thing about this problem is that
everything appeared to be going fine during the queueing and printing.
The PS file just never came out of the printer.