summary(zelig(..., model="oprobit.bayes")) returns error

[Alex Man]

z.out <- zelig(forumla, model = "oprobit.bayes", data = data, cite = FALSE)
summary(z.out)

returns:

Model: Combined Imputations 

Error in UseMethod("vcov") : 
  no applicable method for 'vcov' applied to an object of class "mcmc"

This happens only when the input data set is an amelia object.