exception happened while using WFS and PostGis in Mapserver mapfile

Question

I'm trying to use GML produced by Mapserver to create popup with openlayers, if datasource comes from shp file, everything is working fine, however, postgis datasource brings exception, like "This may be due to a corruption of the heap, which indicates a bug in HTTPFormServer.exe or any of the DLLs it has loaded." Another, if I just read layer data from postgis to render label instead of as WFS, it's working fine as well

who can help tell what happend?

environment: mapserver5.6.1, postgis8.4, openlayers2.10

for shp data source, works

    LAYER
        NAME poi_point
        METADATA
          "wfs_title"         "poi_point" ##REQUIRED
          "wfs_typename"      "poi_point" ## REQUIRED
          "gml_include_items" "all" ## Optional (serves all attributes for layer)
          "gml_featureid"     "ID" ## REQUIRED
          "gml_geometries"    "geometry"
          "gml_geometry_type" "point"
        END
        PROJECTION
            "proj=latlong"
            "ellps=GRS80"
            "datum=NAD27"
        END 


        DATA poi_point
        STATUS ON
        TYPE POINT
        DUMP TRUE
        MAXSCALEDENOM  2400
        CLASS
            STYLE
                COLOR 0 0 0
                OUTLINECOLOR 255 255 255
            END
        END
    END

for postgis datasource, exception happend

LAYER
    NAME poi_point
    DATA "the_geom from poi_point"
    METADATA
      "wfs_title"         "poi_point" ##REQUIRED
      "wfs_typename"      "poi_point" ## REQUIRED
      "gml_include_items" "all" ## Optional (serves all attributes for layer)
      "gml_featureid"     "ID" ## REQUIRED
      "gml_geometries"    "geometry"
      "gml_geometry_type" "point"
    END
    PROJECTION
        "proj=latlong"
        "ellps=GRS80"
        "datum=NAD27"
    END 

    CONNECTION "user=postgres password=springtime dbname=postgis host=localhost port=5432"
    CONNECTIONTYPE postgis
    STATUS ON
    TYPE POINT
    DUMP TRUE
    MAXSCALEDENOM  2400
    CLASS
        STYLE
            COLOR 0 0 0
            OUTLINECOLOR 255 255 255
        END
    END
END

Answer 1

I find it's a bug in mapserver-5.6.1, that is, allocated memory is not enough in msPostGISBuildSQLBox, enlarge is ok.