[R] Incomplete output with `sn' library package

[MANASI VYDYANATH]

Dear R users:
I have a question regarding the output for two of the functions in  
the `sn' package, which deals with the mle fitting of skew normal  
curves to linear regressions. I'm using the examples and the dataset  
given as an example in the online documentation for this package, for  
the functions `msn.fit' and `msn.mle'. I'm following the example code  
in the documentation for these two functions exactly.
Part of the data output is supposed to be "se", which gives the  
standard errors of the estimated coefficients. This particular value  
comes out as being "NA" in the examples given, but there are three  
coefficients in each case and no numerical problems about why the  
standard errors cannot be calculated.
Am I setting this program up right? Is there some other command I  
should use (or an option I need to use) to get the output to display  
standard errors of the coefficients?
Thank you for your time in reading this question -
Cordially,
Manasi