Maybe I just don't understand what is happening to the CVS but...

% ruby -e'1.times {|i; j=i| p[i, j] }'
[0,0]
% ruby -e'{|i; j=i| p [i, j]}.call(0)'
-e:1: [BUG] bug in variable assignment
ruby-1.9.0 (2005-03-10) [powerpc-darwin7.7.0]