Browser treatment of Linked Data resources

Hi,

I have set up a simple Linked Data application which uses an Active
Server Page to parse the initial URL and decide what resource to return
and in what format.  It uses '303 See Other' responses to redirect to
the required serialization, in the approved Linked Data manner.  I have
always used curl to test low-level responses, and Firefox as my browser,
and it all works happily in those environments.

Recently I tried out my application with other browsers: Edge, Chrome
and Opera.  To my surprise, the redirection of the default URL gave
different results from Firefox.  On two of the browsers, it returned the
XML version of the data, and on the other it attempted to return an
image (yes, I have stretched the definition of 'linked data' to suit my
own ends :-)).  So in one case the original URL

http://wt-modes/Object/WTcoll/id/GRMDC.B199

was converted to

http://wt-modes/Object/WTcoll/id/xml/GRMDC.B199

and in the others to

http://wt-modes/Object/WTcoll/id/jpeg/GRMDC.B199

My initial reaction was to assume that the problem was with the '303 See
Other' redirection, so I rewrote the ASP code to deliver the HTML
response directly when no serialization was specified in the initial
URL.  However, this had no effect on the above results.

Given that ASP generates code server-side, and curl reports this:

C:\Program Files\curl\bin>curl -v
"http://wt-modes/Object/WTcoll/id/GRMDC.B199"
*   Trying fe80::6dd9:15e0:b7e0:91a...
* TCP_NODELAY set
* Connected to wt-modes (fe80::6dd9:15e0:b7e0:91a) port 80 (#0)
> GET /Object/WTcoll/id/GRMDC.B199 HTTP/1.1
> Host: wt-modes
> User-Agent: curl/7.58.0
> Accept: */*
>
< HTTP/1.1 200 OK
< Cache-Control: private
< Content-Type: text/html
< Expires: Fri, 02 Mar 2018 19:27:01 GMT
< Server: Microsoft-IIS/10.0
< Set-Cookie: ASPSESSIONIDAQQDBQAS=OGENELKAMKODCMJBONNGGHIK; path=/
< X-Powered-By: ASP.NET
< Date: Fri, 02 Mar 2018 19:27:01 GMT
< Content-Length: 1439
<

I fail to see how these browsers could generate such a different outcome
from Firefox.  Does this chime with anyone else's experience, and does
anyone have a clue to offer me?

Many thanks,

Richard

-- 
*Richard Light*