Which version of Tableau are you using?
You are using 'Number of Values' right now which I can't imagine is correct. Instead, Right click 'User ID' and drag it to the Rows Shelf. When you drop it, select CNTD.
Could you share the sample workbook ?
I have switched to use CNTD User ID - but this does not solve my problem.
p.s. I am using Desktop 9.0
It's attached above.