PIXMAP symbols don't appear

[Czogalla, Olaf]

Dear Mapserver users,

recently we upgraded to Mapserver 4.0.2 and Mapscript 1.177.2.1 w/ PHP version 4.3.1 from an ancient version (PHP 4.0.5 Mapserver 3.4) being aware that this was quite a big step.

Currently I'm struggling to get our maps running again, line and polygon shapes are working fine. One of the major problems instead is caused by PIXMAP symbols for point shapes. 

As the annotation labels for each point show up the symbol image is missing. The symbol is a small PNG file. Assuming palette problems I have tried to use 256 colors and RGB colors for the symbol in combination with both IMAGEMODE PC256 and RGB for the map image. Neither combination works so far. Although using a simple vector symbol for the point shape from symbols.sym does work.  

The relating file snippets look like this:

symbols.sym:
---------------
SYMBOL
    Name 'baustelle'
    Type PIXMAP
    Image 'images/baustelle.png'
END

The map file:
---------------
OUTPUTFORMAT
 NAME png
 DRIVER "GD/PNG"
 MIMETYPE "image/png"
 IMAGEMODE RGB
 EXTENSION "png"
END
.
.
LAYER
  MAXSCALE 25000            
  NAME Baustelle               
  TYPE POINT                   
  STATUS on                     
  DATA baust                     
  LABELITEM 'period_end'   
  CLASSITEM 'period_end'
  CLASS                           
    SYMBOL 'baustelle'
    SIZE 24
    LABEL                           
        FORCE true
        POSITION UC
        TYPE TRUETYPE
        FONT trebuchet_ms-italic
        SIZE 10
        OUTLINECOLOR 255 255 255
        COLOR 0 0 255
        OFFSET 0 -38
        ANTIALIAS ON
    END
  END
END

Any ideas that give me directions are greatly appreciated. Does size of the symbol matter?

Kind regards

Olaf Czogalla
Institut f. Automation und Kommunikation
Steinfeldstr. 3
D-39179 Barleben

Phone +49 39203 810 49        
Fax +49 39203 811 00          
Email   Olaf.Czogalla at ifak-md.de                 
WGS84: 52.1964°N 11.5986°E