php-mapscript: abnormal death

[Mark Leslie]

I'm working with a php-mapscript application that, I'm told, used to
work.  The problem I'm having now is that the script ofter dies on the
$img->saveImage('') call.  Without this call, 'echo' prints values
normally.  When the call is made, nothing is returned, no content, no
headers.  I can output to the apache error log, and anything above the
'saveImage' call will be written properly, nothing after.  It  looks
like php is being abruptly killed during the call and is unable to flush
it's buffer or continue.  No error is reported by php.

The application basically selects one of three sets of layers and
creates graduated classes based on passed in range and color
parameters.  I'm running on some version of redhat, php 4.3.8.  My
mapserver version is as follows:

MapServer version 4.5 OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP OUTPUT=PDF
SUPPORTS=PROJ SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT
SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT INPUT=EPPL7 INPUT=POSTGIS
INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE

Any thoughts would be greatly appreciated,
Mark