Bug in Fisher Exact test?

[Salomon Minkin <minkin@uhnres.utoronto.ca>]

I'm running Version 6.2 on Unix.

I'm surprised that I'm getting  zero  p-values when I'm running the
Fisher exact test on some 3 x 2 tables. Here are two examples:

> fisher.test(matrix(c(0,1,2,0,0,3),nrow=2))

           Fisher's exact test
data:   matrix(c(0, 1, 2, 0, 0 ,3), nrow = 2)
p-value = 0
alternative hypothesis: two.sided

>fisher.test(matrix(c(0,5,3,1,0,1),nrwo=2))

           Fisher's exact test
data:   matrix(c(0, 5, 3, 1, 0 ,1), nrow = 2)
p-value = 0
alternative hypothesis: two.sided

Clearly, there is a positive probability of observing these particular
tables keeping the margins fixed. According to my hand calculations,
the probability of observing the first table is 0.067, and for the
second table
the probability is 0.033.

Why do I get a p-value of zero?

Thanks,

Salomon