R help - Apr 2006 - svyby example returns error

I get error trying to run examples from 'svyby' help page (?svyby in
package "Survey"):

  # code
data(api)
dclus1<-svydesign(id=~dnum, weights=~pw, data=apiclus1, fpc=~fpc)
svyby(~api99, ~stype, dclus1, svymean)
  # error message
> Error in match.arg(vartype, several.ok = TRUE) :
        unused argument(s) (several.ok ...)

Is this a version problem? I'm running R Version 2.1.0  (2005-04-18,
i386-pc-linux-gnu) and have installed survey_3.4-4.tar.gz using
install.package("survey", dependencies=T).

I'd be grateful if somebody would trace the problem. I've got as far as
locating this bit of code from 'svyby' function, but can't tell much
out
of it, for arguments to 'match.arg' seem ok:
...
 if (missing(vartype))
        vartype <- "se"
    vartype <- match.arg(vartype, several.ok = TRUE)
    nvartype <- pmatch(vartype, eval(formals(sys.function())$vartype))
...

Thanks in advance,
Martin

Martin Pozar wrote:
> I get error trying to run examples from 'svyby' help page (?svyby
in
> package "Survey"):
Yes, it's a version error I guess. Debian stable (Sarge) version of R is
obsolete, so I had to get a backport and it works fine:
http://cran.r-project.org/bin/linux/debian/README

This list is not for getting help on problems that arise from using
obsolete versions of R. Get the latest version.

And this list is not for getting help on contributed packages such as
"Survey" (and most others downloaded from CRAN), even if there are
related queries and answers present in the archive. Contact the author
of the package first.

And
> PLEASE do read the posting guide *carefully and twice*!
http://www.R-project.org/posting-guide.html
Thank you, Mr. Ripley. :)

Regards,
Martin