query with return distinct values in rest services get error when tables joined

I query using return distinct values in rest services works fine.
Under the same circumstances, ARCGIS server 10.1 sp1, I joined tables to the feature class.
I queried a field in the table without using return distinct values, it returns results fine.
Once I queried the field in the table using return distinct values = true, it throw "Error performing query operation"

Settings on ArcGIS REST Services Directory as below,

Where: Division.Division LIKE '%'
Out Fields: ProjectNumber.ProjectTitle
Return Geometry: False
Return Distinct Values: True

Anything I missed? Thanks for any help in advanced.