I think the reason my fix works is this;
You are building a HOH by adding to it at each start_tag here - 
$pos[$depth] = \${$pos[$depth - 1]}->{$element->{Name}};

[download]
If later, you allow a text string to be assigned to $pos[$depth] then at the next depth the program fails because \${$pos[$depth - 1]} is now not a hash reference.
The text string should only be assigned when you reach the lowest level. In your XML data this conveniently is when there are no line breaks in the data. This is a big assumption and I would not do this for a serious application - much better to use the proper tools.
Hope this helps, I too am learning from this
poj

In reply to Re: Re: Setting the value of a complicated hash ref by poj
in thread Setting the value of a complicated hash ref by blahblah

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.