error "CLIENT reliev a text/html and not text/xml " with sample.net   

I install XML for Analysis on Win Srv 2000 with IIS 5.1, MSXML 6 and Virtual 
Directory xmla.
But I can't use sample.net or simly go to http://localhost/xmla/msxisapi.dll 
but give back internal serve error!

I don't even succeed to starting the sample. net
HELP!

date: Thu, 26 Jan 2006 15:47:12 +0100   author:   Dario Concilio [MCP]