Konrad,
I have found XML construction to be a bit finickywhen I am using Visual Foxpro and the ServerXMLHTTP request object. In some XML I have that looks similar to yours (defining "Field" values), I use these two lines as my XML headers:
<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type="text/xsl" href="/DocuWare/Platform/Content/standard.xslt"?>
Let's see if I have a longer <Document> example...here's one:
<?xml version="1.0" encoding="utf-8"?>
<?xml-stylesheet type="text/xsl" href="/DocuWare/Platform/Content/standard.xslt"?>
<Document xmlns:s="http://dev.docuware.com/schema/public/services" xmlns="http://dev.docuware.com/schema/public/services/platform">
<Fields>
<Field FieldName="{fieldname}">
<{fieldtype}>{value}</{fieldtype}>
</Field>
</Fields>
</Document>
It looks like you might be lacking the second line in the XML headers, the one that establishes stylesheet type?
If you are more familiar/comfortable with JSON, you might try that. It seems easier to construct, but I did not have much luck with it. But maybe I was not setting my request headers appropriately. JSON seems to be the thing a lot of web-based services are leaning towards, tohugh DocuWare still stores a LOT of stuff as XML in their back-end database (like embedded properties).
Hope this helps. Getting Playform Service stuff working in anything other than .NET has always been a struggle from what I see on the forums.
Thanks,
Joe Kaufman