Mapserver and WMS

[Subscribe Mapserver-Users Gom]

I have a Mapserver demo running on IIS 5 and trying to get it going on IIS
6.  I have been playing with the WMS aspects of it and have the following
behaviour.

Using a client called Jump, I can get to the data.  The extents are not
recognized but if I pan and zoom to the right lace my map is there with
all its layers anbd thematic styles etc.  Works as expected accept for the
extents.

Using Cadcorp SIS map browser, the getcapabilites URL generates an error
saying "End tag 'BODY' does not match the start tag 'br'."

Using ArcCatalog, I can add the URL and get a report of all layers etc.  I
can add it to ArcMap and the map will zoom to the correct extents.  All
layers show up in the ArcMap legend but all are greyed out.  I cannot see
any map data nor can I adjust any of the settings such as zoom in or out
levels.  I zoom way in and way out but nothing shows up.  I can always
zoom extents and it takes me back to the correct extents. (I can only say
that the extents of the blank window fall within the area covered by the
map.)

Is this typical of how WMS clients are implemented?  Any thoughts others
could share on what might be going on with my installation or map file etc.

Thanks