[ESS] evaluation problem in ESS

[Ross Boylan]

I have some code that runs OK outside of ESS, but inside I get
Error in mspath(states ~ times, qmatrix, misc = SIMPLE, ematrix, inits,  : 
	object "SIMPLE" not found

The original line is like
r <- mspath(states~times, qmatrix, misc=SIMPLE, ematrix,
            inits, subject=c(rep(1,4), rep(23, 3)),
            covariates = ~ cov1 + cov2,
	    [many more arguments])

and misc is an argument that the function plays games with via substitute:
        if (as.character(substitute(misc)) == "SIMPLE")

Originally I was trying to pull this line in from another file (that
is, outside of R session).  But even when I tried pasting the command
into the R/ESS buffer and executing I got the error.

Is there a way around this?

Thanks.