Having trouble changing from a4 to letter paper size.

[Ryan M. Rifkin]

I'm trying to print out my score on letter paper.  According to the
manual, you have to set papersize at top level.  So not in any braces,
before the \paper block, I have (including the paper block):

papersize = "letter"
\paper {
  indent = 0.0\mm
}

If I replace the papersize command with

papersize="a4"

or omit it entirely, the dvi file generated is identical (assuming I
generate them within the same minute --- it appears that the dvi file
have some sort of timestamp based on the minute inside them?)

How do I change the papersize?  Right now, the music is running off
the bottom of my paper.

rif