WordPress Crash on long post content

I have a weird problem with my wordpress theme! when i input a content in page content editor in wordpress’s admin, if the content’s height is more than 25 lines, apache server (xampp) shows this error:

Problem signature:
  Problem Event Name:   APPCRASH
  Application Name: httpd.exe
  Application Version:  2.2.11.0
  Application Timestamp:    493f5d44
  Fault Module Name:    php5ts.dll
  Fault Module Version: 5.2.9.9
  Fault Module Timestamp:   49a56925
  Exception Code:   c00000fd
  Exception Offset: 00151f0a
  OS Version:   6.1.7600.2.0.0.256.

what is the problem and how can i solve it?

P.S. my page.php file is this:

<?php get_header(); ?>
 <div id="middleDiv" >

<div id="pageDiv" align="center">

<div id="singlePageDiv" >

                <?php
the_post();

the_content();

    ?>

</div><!--singlePageDiv-->
    <?php get_footer(); ?>
    </div><!--pageDiv-->

</div><!-- #middleDiv -->