projection question

[Stephen Woodbridge]

Hi all,

I am trying to reproject some shapefiles using perl/mapscript. The 
script seems to be working as I have used it with great success in the past.

So I have been trying various input and output projections using the 
following definitions:

my $prjin = 'proj=latlong,ellps=clrk66,towgs84=89,-279,-183,0,0,0,0';

# NAD83
my $prjout = "init=epsg:4269";

# or WGS84
#my $prjout = "init=epsg:4326";
#my $prjout = "proj=latlong,datum=WGS84";

The data gets reprojected just fine but it seems to only move about half 
the distance that I need it to, to lineup with my other data set. So I 
have tried to push it a little further by changing the towgs84 
parameters, but I can't seem to make it move! For example changing -279 
to -1279 does not move the geometry relative reference geometry that is 
not reprojected!

Any thoughts on how to get this to move using proj? It just seemed like 
a better way to go than to add dx, dy to all the shape points by hand.

-Steve W.