Visual Build Pro - Build Analysis Services Cube with MySQL datasource - build

Question

I am trying to create a build script using Visual Build Pro v7 for an Analysis Services Cube I have created. The cube deploys to my local machine without issue using the following build script steps...
Other than replacing the target server in the .dwproj.user file, backing up and removing any traces of a possible previous version of the cube, my build script just contains the steps:
Step 1 : "%VS2008IDE%\devenv.exe" "%PROJDIR%\%CUBE_NAME%.sln" /Build
Step 2 : "%SSAS_Deploy_EXE%" "%PROJDIR%\%CUBE_NAME%\bin\%CUBE_NAME%.asdatabase" /s /o:"%PROJDIR%\deployscript.xmla"
Step 3 : "%ASCMD_LOCATION%" -S %CUBE_SQL_INSTANCE% -U DOMAIN\%UID% -P %PWD% -i "%PROJDIR%\deployscript.xmla"
The cube's data source is a MySQL db. The build fails on Step 3 when deploying to a remote server.
I have downloaded and installed MySql Connector/Net on the server, but when I run the build script I get the following error:
<return xmlns="urn:schemas-microsoft-com:xml-analysis">
<results xmlns="http://schemas.microsoft.com/analysisservices/2003/xmla-multipleresults">
<root xmlns="urn:schemas-microsoft-com:xml-analysis:empty"/>
<root xmlns="urn:schemas-microsoft-com:xml-analysis:empty">
<Exception xmlns="urn:schemas-microsoft-com:xml-analysis:exception" />
<Messages xmlns="urn:schemas-microsoft-com:xml-analysis:exception">
<Error ErrorCode="3238002695" Description="Internal error: The operation terminated unsuccessfully." Source="Microsoft SQL Server 2008 R2 Analysis Services" HelpFile="" />
<Error ErrorCode="3239116921" Description="Errors in the back-end database access module. The managed provider 'MySql.Data.MySqlClient' could not be instantiated." Source="Microsoft SQL Server 2008 R2 Analysis Services" HelpFile="" />
<Error ErrorCode="3239182436" Description="Errors in the high-level relational engine. A connection could not be made to the data source with the DataSourceID of 'Linkdex', Name of 'Linkdex'." Source="Microsoft SQL Server 2008 R2 Analysis Services" HelpFile="" />
<Error ErrorCode="3240034316" Description="Errors in the OLAP storage engine: An error occurred while the dimension, with the ID of 'Keyword', Name of 'Keyword' was being processed." Source="Microsoft SQL Server 2008 R2 Analysis Services" HelpFile="" />
<Error ErrorCode="3240034317" Description="Errors in the OLAP storage engine: An error occurred while the 'Project Id' attribute of the 'Keyword' dimension from the 'LinkDexCube' database was being processed." Source="Microsoft SQL Server 2008 R2 Analysis Services" HelpFile="" />
<Error ErrorCode="3239837698" Description="Server: The operation has been cancelled." Source="Microsoft SQL Server 2008 R2 Analysis Services" HelpFile="" />
</Messages>
</root>
<root xmlns="urn:schemas-microsoft-com:xml-analysis:empty"/>
</results>
</return>
When I check the .asdatabase and .xmla I can see that the user id and password details from my ConnectionString have been removed. I'm not sure why this is or where this happens?
Does anyone have any ideas what's happening? Is it likely to be a permissions issue or something to do with the mysql connector? Or some third option?