Psych Library polychoric Function Error "You have more than 8 categories for your items, polychoric is probably not needed"

I'm new to R and running into an error with the polychoric function in the psych package. I'm attempting to store the polychoric correlation matrix in a data frame from using the following syntax:

RPOL36 <- polychoric(norm.kdqol36,smooth=TRUE)

where norm.kdqol36 is a data frame with vectors of ordered variables, each with 5 levels (0, 25, 50, 75, 100). Here is an example:

0 25 50 75 100 11962 19953 4987 12998 8261

Despite each variable having 5 levels, I get this error:

Error in polychoric(norm.kdqol36, smooth = TRUE) : You have more than 8 categories for your items, polychoric is probably not needed

Could there be a formatting issue causing the polychoric function to read my variables as having more than 5 categories?