Thanks very much for all the feedback I got on PS viewers.
In fact, only a week ago, I downloaded gv 3..5.8, managed to compile it and
it worked fine. I then had to upgrade my gs5.50 to gs6.50 to handle
computer modern type 1 fonts. Now, gv no longer works. It gives
Postscript interpreter failed on main page.
That's weird. I just tried the same gv 3.5.8 with both
gs5.50 and gs6.50 and it works without any problems.
Are you sure that you didn't compile in any full paths to
gs in the gv binary? In State-Ghostscript options ...,
it should just say Interpreter: gs