weird predict function error when I use naive bayes

Hi,

I tried to use naivebayes in package 'e1071'.
when I use following parameter, only one predictor, there is an error.

 m<- naiveBayes(iris[,1], iris[,5])
 table(predict(m, iris[,1]), iris[,5])

Error in log(sapply(attribs, function(v) { :
   Non-numeric argument to mathematical function


However, when I use two predictors, there is not error any more.

 m<- naiveBayes(iris[,1:2], iris[,5])
 table(predict(m, iris[,1:2]), iris[,5])

setosa versicolor virginica
   setosa         49          0         0
   versicolor      1         37        19
   virginica       0         13        31

Do you know what is the problem?

Br,
Luffy