Using the example in: http://cran.r-project.org/web/packages/Zelig/vignettes/probit.pdf If I add robust=TRUE, I get the following error:> z.out <- zelig(vote ~ race + educate,mode="probit",data=turnout,robust=TRUE) Error in glm.control(robust = TRUE) : unused argument(s) (robust = TRUE)Thoughts? Thank you,bp