[AccessD] combo box 101

This ought to be a piece of cake. I have a combo with rowsource:

Select 	Source, 
	Level1Basis as [Customer Level], 
	ReportName 
from 
	TblReportHeaders 
where 
	Source = [forms]!frmMatchReport![cboBasis] 
	and 
	level1basis = [forms]!frmmatchreport![cbobasislevel1]

Columncount = 3.
In terms of the display problem I am having, it doesn't seem to matter
whether ColumnWidths is left blank, or I enter 0.5";1.5";3".
What I want to show in the text portion of the combo is the 3rd field,
[ReportName]

But what keeps being displayed after a selection, is the 1st column (Source)

Bound Column has been alternately set to 0, 1, or 2 ... it makes no
difference.