OPENQUERY error OLE DB provider "SQLNCLI10" for linked server "linked_olap" returned message "Syntax error, permission violation, or other nonspecific error".

Hello, 

HELP!  I'm trying to use OPENQUERY to return data from a cube, like this.

SELECT * 
FROM OpenQuery(linked_olap,'SELECT --measures.members 
 {Measures.[Internet Sales Amount]} ON COLUMNS, 
 [Date].[Month].members ON ROWS 
FROM [Adventure Works]')

The query is running from SSMS on the same server as the cube.  I created a linked server usingsp_addlinkedserver

and granted data access with sp_serveroption.

However, I'm getting this error.

OLE DB provider "SQLNCLI10" for linked server "linked_olap" returned message "Syntax error, permission violation, or other nonspecific error".

This thread gives a partial answer, but I'm not sure how to employ it. 

http://social.msdn.microsoft.com/Forums/en-ZA/transactsql/thread/543026e6-4f18-4733-ab5f-43cc4486f5e3

The chosen answer in the thread says the "first" project is accessible.

Apparently when there are two analysis services projects on a linked ssas server, only the first one is accessible.

How do I know which is the "first" project?  Can I set that somehow?  There are many projects on this server.  Can anyone shed any light on this? Is this a red herring entirely?   Eeek!

I hope this is posted in the correct place. If not, mods feel free to move.

Thanks in advance for any help anyone can provide - it's very much appreciated!