Zelig, oprobit error

Hello,

I'm getting an error message when I use the ordered probit model 
"oprobit" in the zelig function.  Using the same form as in the help 
file, we get an error message.  It produces coefficients, but no 
standard errors.  See results below.  Any hints?

Thanks!

 > 
 > o.probit <- zelig(as.factor(checks.change) ~ Oda + Oil + sh_neg + 
sh_pos + checks1, model="oprobit", data=data.all)
 > summary(o.probit)
Error in svd(X) : infinite or missing values in 'x'
 > o.probit$coefficients
       Oda        Oil     sh_neg     sh_pos    checks1 
 2.858e-02  1.978e-07 -1.961e-02  4.810e-02  8.492e-02 
 >