Most in this thread already is beyond my knowledge of the internal workings,
but I can contribute that I got this error on a:
Debian 4.0 box with Perl v5.10.0 built for i486-linux-gnu-thread-multi with these module versions: 
perl -d:Modlist -e " use strict; use warnings; use XML::Twig; "
AutoLoader             5.63
Carp                   1.08
Config                     
DynaLoader             1.08
Encode                 2.23
Encode::Alias          2.07
Encode::Config         2.04
Encode::Encoding       2.05
Exporter               5.62
Exporter::Heavy        5.62
File::Basename         2.76
File::Glob             1.06
File::Spec           3.2501
File::Spec::Unix     3.2501
List::Util             1.19
Scalar::Util           1.19
UNIVERSAL              1.04
XML::Parser            2.41
XML::Parser::Expat     2.41
XML::Twig              3.39
XSLoader               0.08
base                   2.13
bytes                  1.03
overload               1.06
re                     0.08
utf8                   1.07
vars                   1.01
warnings               1.06
warnings::register     1.01
and on
Ubuntu 11.04 with Perl v5.10.1 (*) built for i686-linux-gnu-thread-multi.

In reply to Re^4: Segmentation fault from XML::Twig::Elt by isync
in thread Segmentation fault from XML::Twig::Elt by isync

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.