Hey all, I am getting an error when I add a #to_s method to NSURL: ± irb irb(main):001:0> class NSURL irb(main):002:1> alias_method :to_s, :absoluteString irb(main):003:0> end => NSURL irb(main):004:0> NSURL.URLWithString( 'macruby.org' ) RuntimeError: can't modify frozen/immutable string irb(main):005:0> test = NSURL.URLWithString( 'macruby.org' ) RuntimeError: can't modify frozen/immutable string irb(main):006:0> test.to_s => "macruby.org" irb(main):007:0> So the error seems to be macirb trying to do something to the string that is returned from #to_s. I'm not sure if this is unique to MacRuby, as the CRuby documentation for Object#to_s doesn't say whether the returned object should be frozen, but should I be making #to_s return a mutable/unfrozen string? Mark Rada mrada@marketcircle.com