JRuby demonstration exhibiting Matrix failure

gistfile1.txt

$ ruby ./matrix_test.rb 
Attempting to create a matrix
a = [
  [1, 2, 3]
  [:a, :b, :c]
  ["x", "y", "z"]
  ["#", "%"]
]
Matrix.columns(a)
Matrix[[1, a, x, #], [2, b, y, %], [3, c, z, ]]

$ jruby ./matrix_test.rb 
Attempting to create a matrix
a = [
  [1, 2, 3]
  [:a, :b, :c]
  ["x", "y", "z"]
  ["#", "%"]
]
Matrix.columns(a)
ExceptionForMatrix::ErrDimensionMismatch: Matrix dimension mismatch
    Raise at /usr/java/jruby/lib/ruby/1.8/e2mmap.rb:167
    Raise at /usr/java/jruby/lib/ruby/1.8/e2mmap.rb:87
     rows at /usr/java/jruby/lib/ruby/1.8/matrix.rb:139
     each at org/jruby/RubyArray.java:1572
     rows at /usr/java/jruby/lib/ruby/1.8/matrix.rb:138
  columns at /usr/java/jruby/lib/ruby/1.8/matrix.rb:151
   (root) at ./matrix_test.rb:12