WMS and SRS issue

[Ryan Ollerenshaw]

Question 1:
I am using the SRS 4326 when trying to display a .tif image of canada.  When i
set the extent on the top of the map file to: EXTENT -180 -90 180 90 i am only
getting a very small portion of the map, so i assume that the units begin used
by the extend are meters.  I want to be able to specify the extent by lat/long.
 How can i do this?

Question 2:
When using the web browser as a client my image displays just fine, but when i
try to connect to the same URL in ArcMap or uDig I can see the layers info but
no image gets displayed.  uDig reports an error (Unable to decode image
returned from the server)

Thank you for any help that you can provide.

WMS URL:
http://neuron/cgi-bin/mapserv?map=../html/mapserver/htdocs/mywms.map&
          SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&LAYERS=test_layer

Map FILE:
NAME WMSDEMO
STATUS ON
SIZE 500 400
EXTENT 0 0 2800 2800
#EXTENT -180 -90 180 90
#EXTENT -2200000 -712631 3072800 3840000
#UNITS METERS
SHAPEPATH "../data"
IMAGECOLOR 255 255 255

WEB
  TEMPLATE test_template.html
  IMAGEPATH "/tmp/ms_tmp/"
  IMAGEURL "/ms_tmp/"
  METADATA
    WMS_TITLE   "WMS test mapserver"
    WMS_ACCESSCONSTRAINTS "none"
    WMS_ONLINERESOURCE "http://neuron/cgi-bin/mapserv?map=mywms.map&"
    WMS_SRS     "EPSG:4326" #"AUTO:42003"
  END
END

PROJECTION
  "init=epsg:4326"
END

LAYER # Shaded Relief Raster
  NAME test_layer
  DATA bath_mapserver.tif
  STATUS ON
  TYPE RASTER

  METADATA
    WMS_TITLE "Shaded Relief Map of the Upper Great Lakes Region"
    WMS_ABSTRACT "Shaded Relief Map, clipped from National Atlas dataset"
    WMS_SRS "EPSG:4326"
    WMS_FORMAT "image/png"
  END

END


END # of map file