Drop down list with unique values is showing no data in graph when (none) is selected, I require all/unfiltered data to be shown.

[Stacey McWaters]

Hi, Ive linked a drop down list with unique values in column to a graph and have selected 'Include (none) alternative' with the intension of it showing all/unfiltered data - however, its returning no data inmy graph instead. The other selections work perfectly, its just the (none) is showing nothing when i want it to show everything. Are you able to help me figure this out please

Further info if any of this helps:

Im in Spotfire 10

Thecolumn selected is a calculated column

I cannot change from 'unique values in column' to any other optionbecause the values may change regularly

Expression used in 'Limit data using expressions' on graph:[so_name]=DocumentProperty('ApproverList') - I have tried at least 5 variations of this though.