Using raster in maps without extents breaks map drawing

[bear@…]

If extents is not specified, and a raster layer is included (in my case TIFF
with the appropriate world files), mapserver quits quits with te following

Warning: MapServer Error in msCalculateScale(): Invalid image extent. in
/var/www/html/gis/sfsql/index_xml_attrib.m on line 118

If there is no raster layer, mapserver works even if the extents are not set. If
the map extents are set, the map drawing works. Problems:

1. Error message is wrong, the IMAGE extent is valid, the MAP extents are those
that are not specified.
2. The extents are not invalid, but rather not specified
3. Inconsistent behaviour - the maps are not getting drawn ONLY if there are
raster layers in the map. _ARC, _LINE _POLYGON _ANNOTATION layers are not
bothered by the lack of defined extents in the map.