Terraservice data not aligning

[Camden Daily]

I think the TIGER data is quite incredible for being free.  Even if
it's not perfectly accurate, it's certainly good enough for most
applications.  In fact, if I wasn't trying to overlay it on the
terraservice data, I wouldn't have even noticed that it was off.

I only need data for the state of Illinois, and while they have some
good GIS data on the state web site, it doesn't include street level
data.

I have a question about WMS layers in Mapserver.  When I get the layer
from terraservice, I use the lines:

    CONNECTION
"http://terraservice.net/ogcmap.ashx?VERSION=1.1.1&SERVICE=wms&LAYERS=urbanarea&FORMAT=image/jpeg&STYLES="
    METADATA
     "wms_srs" "EPSG:4326"
    END

Now, I assume that mapserver also sends it the extents that are
needed.  Is there a way I could tweak those extents before they get
sent to terraservice?  If I could offset them just slightly to match
my TIGER data, that'd be wonderful.

Thanks for the help everyone,
-Camden