The same script used to work ok, but it suddently stopped working.

If that's true then the prime suspect is that a different data set or structure is being fed to the script.

In addition to the other excellent responses already given in this thread it might be beneficial to point out the FAQ How can I check if a key exists in a multilevel hash? which covers this topic.

In reply to Re: Strange Hash related bug, keys are created by themselves! by hippo
in thread Strange Hash related bug, keys are created by themselves! by mak007

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