Version 4.4.1 dependency and/or linux platform dependency?

[Brian Davis]

I originally posted this under a reply to a problem with distorted maps.
This is the same text, under a new subject with version and platform
dependency type words:

I have been struggling with projection, extents, and size
for a couple of days now.

When I zoom in to a map, the four corner points of my rubber-band box
are the new corners for the data displayed in my 400x200 browser space.
So, if I define an area that is 2:1 in x size to y size, I zoom in
as expected.  But when defining space that is not this 2:1 rectangular
ratio, the data gets stretched/contracted/distorted to fit that space,
because the corners of my new definition become the drawn corners,
instead of extra data in either the x or y direction being used to
fill the the remaining area.

Previously, interfacing to mapserver 4.0.2 on a Windows platform worked
just fine.
Currently, interfacing to mapserver 4.4.1 on a Red Hat Enterprise server
shows these symptoms.
I changed NONE of the html, js, or java, except all I did was point to a
new url with the linux mapserv, and the corresponding new location for
the .map file.

Is there a platform-dependency I am not worrying about correctly?
Is there a version-dependency I am not worrying about correctly?

Perhaps the answer is to point me at the correct discussion thread
dealing with these issues?  I couldn't find anything useful after a few
searches, so thought I would send out a post while I'm still looking.

Thanks!

Here are the relevant snippets from my .map file:

EXTENT -180.000 -90.000 180.000 90.000
SIZE 400 200
TRANSPARENT ON
UNITS DD

PROJECTION
    proj=longlat
    ellps=WGS84
    datum=WGS84
    no_defs
    "init=epsg:4326"
END