R help - Dec 2011 - MCMCglmm error with multinomial distribution

With binomial/binary responses (0|1) running MCMCglmm with
family="multinomial" terminates with

Error in if (nJ < 1) { : missing value where TRUE/FALSE needed

with family="categorical" there are no errors

I have not looked in the code, do I need format the responses
TRUE/FALSE , or is this just a bug?

-- 
H?vard Wahl Kongsg?rd