[R] box.Cox.powers() warning

[cmhcordei at gmail.com]

Dear Rlist,

Using an example in box.cox.powers() help, I have the following warning message.

example:
library(car)
>attach(Prestige)

> box.cox.powers(income)
Box-Cox Transformation to Normality 

 Est.Power Std.Err. Wald(Power=0) Wald(Power=1)
    0.1793   0.1108        1.6179       -7.4062

L.R. test, power = 0:  2.7103   df = 1   p = 0.0997
L.R. test, power = 1:  47.261   df = 1   p = 0 
Warning message:
In optimize(f = function(lambda) univ.neg.kernel.logL(x = X[, j],  :
  NA/Inf replaced by maximum positive value

I do not know the reason for such warning message. 
Can someone help me on this matter?

Best regards, 
Clara Cordeiro

> sessionInfo()
R version 2.6.1 (2007-11-26) 
i386-pc-mingw32 

locale:
LC_COLLATE=Portuguese_Portugal.1252;LC_CTYPE=Portuguese_Portugal.1252;LC_MONETARY=Portuguese_Portugal.1252;LC_NUMERIC=C;LC_TIME=Portuguese_Portugal.1252

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] nnet_7.2-38    car_1.2-7      MASS_7.2-38    FitAR_1.0      leaps_2.7     
[6] lattice_0.17-2

loaded via a namespace (and not attached):
[1] grid_2.6.1  tools_2.6.1