I've had this yesterday, and now a colleague called me with the same problem.
A combo is set like this:
This.ControlSource="this.parent.nGroup_no"
This.RowSourceType= 6
This.BoundColumn=2
This.Style=2
This.RowSource="groups.descript,group_no"
This.BoundTo= .T.
This.ColumnWidths=Transform(This.Width)+",0"
Symptoms: there is never a displayvalue. In the debugger and in code it is always an empty string. Visually, it looks as if disabled. The dropdown does show the list, and if selected, the value gets into combo.value and into this.parent.nGroup_no. The displayvalue remains "".
Workaround:
This.AddProperty("aSPG[1,2]")
Select descript, group_no From groups Into Array This.aspg
This.RowSourceType= 5
This.RowSource="this.aSPG"
...with the rest being the same.
It seems to be that this particular combination of controlsource being a property of an object, boundcolumn being other than 1 and having a boundto=.t. and rowsourcetype of 6 is what yields this behavior. There are other combos on the same container, with this.parent.otherproperty for controlsource, but they have just one column, and they behave fine.
Anyone else seen this? Just want to know if this is a known bug or not.
[Update]
I've been told that this is an old bug. I wasn't using numeric bound columns in combos for a few years now and have forgotten about it. Seems to be it wasn't fixed meanwhile.