Raster image cuts off 10%, sometimes mirrored, repeats

[James Martin]

Hello,

I've got a 8192x4096 tiff of the earth ("Blue Marble" by NASA) that I am
trying use as a raster layer on my map.  My starting extent is -180 -60 180
83 which covers almost everything besides Antartica.   When added as a
layer, the image  that is output overlays perfectly and matches up with my
country outlines, except for the leftmost 10% (About the midpoint of Alaska
all the way to -180)--it doesn't display at all except for my country outline.

In addition, if I try to produce a larger output file, say 1000x500, the
blue marble layer's rendering is mirrored, however everything is displayed.

In both cases, when I zoom in the output is all correct.  The blue marble
layer also repeats/wraps.  If I pan left at my original extent so that
Alaska is now in the middle, Asia will appear to the left of Alaska, but
nothing else wraps and I'd like to prevent this if possible.

Any insight into these issues is greatly appreciated.  I have included some
info from my files that may or may not be helpful.

WORLD FILE
0.0439453125
0.0
0.0
-0.0439453125
-180
90


LAYER
  NAME         blue_marble
  DATA         "raster/ev11656_land_shallow_topo_8192-8bit.tiff"
  STATUS       default
  TYPE         raster
  PROJECTION
    "init=epsg:4326"
  END
END

Projection of my mapfile:

PROJECTION
  "proj=merc"
  "ellps=GRS80"
  "lon_0=0"
  "lat_ts=0"
  "no_defs"
END

-James