setFilter does not always work

[bear@…]

I have a problem with setFilter

I have a layer in my .map file that goes:

LAYER
  NAME "inside"
  CONNECTIONTYPE mygis
  CONNECTION "localhost:user:pass:rzs:bin:"
  DATA "geometry from okrug feature, okrug_bin geometry"
  STATUS ON
  TYPE POLYGON
  FILTER "f_ID=1"
  CLASS
    COLOR 0 155 155
  END
END

and filtering works fine. However, if I try this from phpmapscript

$layer = $map->getLayer(0);
$layer->setFilter("f_ID=1");

mapscript fails when I call $map->draw it aborts with

MapServer Error in msDrawMap(): Failed to draw layer named 'inside'

this happens regardless of what I try to set the filter to.

[bear@…]

string cutting in the parser happens at _, too :(

*** This bug has been marked as a duplicate of 242 ***