To my knowledge, you cannot return a hash, you have to return a reference from your sub, so return \%new_hash, and in your main code: 
my $ref = duplicate_probe_signals(\%clocks);
my %new_hash = %$ref;

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Hope this helps.. -malloc

In reply to Re: more fun with references and hashes by malloc
in thread more fun with references and hashes by diarmuid

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