[oXygen-user] DocBook image scale issue

I have this bit of code: <mediaobject> <imageobject> <imagedata fileref="figures/figures.png" format="PNG" scale="50"/> </imageobject> </mediaobject> I believe this is correctly specified as per the specs. However, when I generated my PDF, the image was displayed as if I had not used scale at all (which is actually a little larger that 100%, which is why I want to use scale). When I turn of FOP output, I see this: [ERROR] Error in content-width property value '50%': org.apache.fop.fo.expr.PropertyException: No conversion defined [ERROR] Error in content-height property value '50%': org.apache.fop.fo.expr.PropertyException: No conversion defined Any ideas as to what I've done incorrectly?