PHP Mapscript: Call to undefined method ms_layer_obj::removeClass()

[Alessandro Pasotti]

Running
$ /var/www/cgi-bin/mapserv -v
MapServer version 4.6.0-beta3 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP 
OUTPUT=PDF OUTPUT=SWF OUTPUT=SVG 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

$ /usr/bin/php -v
PHP 5.0.4 (cgi-fcgi) (built: Aug 30 2005 14:25:17)

The layer object exists and is correctedly instanciated with numclasses = 4 
but I've got the am error.

Is this a bug or something wrong with my installation?

Regards
-- 
Alessandro Pasotti
ICQ# 245871392
Linux User #167502