SYMPTOM:
When accessing MDX Cube Catalog for Microsoft Analysis Service 2008 instance in Strategy Desktop, the following error message appears.

In DSSErrors.log, the following errors are captured.
2013-09-23 01:13:57.566-05:00 XMLA Connect: >> XMLA;URL=
{http://TS-SQL-2008.labs.Strategy.com/OLAP/MSMDPUMP.DLL};CATALOG=
{AdventureWorks DW};UID={labs}; << has invalid UID/PWD combination.
2013-09-23 01:13:57.570-05:00 XMLA Discover failed. SOAP Error.
Error type: XMLA error. XMLAError: <faultcode>XMLAnalysisError.0xc1180001
</faultcode><faultactor></faultactor><faultstring>Either the user, NT
AUTHORITY\IUSR, does not have access to the xxx database, or the database
does not exist.</faultstring><detail><Error xmlns=http://schemas.xmlsoap.org/
soap/envelope/ ErrorCode="3239575553" Description="Either the user, NT
AUTHORITY\IUSR, does not have access to the AdventureWorks DW database, or
the database does not exist." Source="Microsoft SQL Server 2008 R2 Analysis
Services" HelpFile="" ></Error></detail>. The embedded SOAP error is:
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body><soap:Faultxmlns="http://schemas.xmlsoap.org/soap/envelope/">
<faultcode>XMLAnalysisError.0xc1180001</faultcode><faultstring>Eitherthe
user, NT AUTHORITY\IUSR, does not have access to the AdventureWorks DW
database, or the database does not exist.</faultstring><detail>
<Error ErrorCode="3239575553" Description="Either the user, NT AUTHORITY\IUSR,
does not have access to the xxx database, or the database does not exist."
Source="Microsoft SQL Server 2008 R2 Analysis Services" HelpFile=""/>
</detail></soap:Fault></soap:Body></soap:Envelope>. Connection String: .
SQL Statement: DISCOVER_DATASOURCES