Parameter for OLAP datasource -- This prompt value is of an invalid value

I'm running Pentaho BI Server 5.01 CE and PRD 5.01 on an Ubuntu 12.04 machine.

I have a report based on an OLAP datasource. I am trying to add a parameter to it.

I had a WHERE clause like this:
WHERE [Dim Date.YearNum].[All Dim Date.YearNums].[2013] -- hard-coding 2013 as the year. To change it to use a parameter, I changed it to:
WHERE strToMember(Parameter("sYear", STRING, "[Dim Date.YearNum].[All Dim Date.YearNums].[2013]"))

The preview looked OK ... so I added the parameter:
Name: sYear
Label: Year
Value Type: String
Value: [Vw Dim Year.YearNum]

When I attempt to run the report and I input 2013 in the Year prompt, I get a mesage that says "This prompt value is of an invalid value".

Additionally, when I look at the exception indicated by the little red circle in the lower right, I find "java.lang.Float cannot be cast to java.lang.Integer" .... and a long series of messages ending with a statement that it couldn't parse the MDX query.

Can anyone tell what I'm doing wrong?

Thanks!