note IlyaM Similar problem can be reproduced on perl 5.8.0 too. Minimal test case: <code> use Data::Dumper; $Data::Dumper::Sortkeys = sub { [ sort keys %{$_[0]} ] }; print Dumper({}, {}); </code> <div class="pmsig"><div class="pmsig-127307"> <p> <font color="grey" size="-2"> --<br> Ilya Martynov, <a href="mailto:ilya@iponweb.net">ilya@iponweb.net</a><br> CTO IPonWEB (UK) Ltd<br> Quality Perl Programming and Unix Support UK managed @ offshore prices - <a href="http://www.iponweb.net">http://www.iponweb.net</a><br> Personal website - <a href="http://martynov.org/">http://martynov.org</a><br> </font> </div></div> 301633 301633