Can't say I've ever seen this before, but here's what doesn't look right:
Your combo rowsource is
Code:
SELECT ExtHelperValueID, ExtHelperID, ExtHelperValue FROM tblExtHelperValue WHERE ExtHelperID = cboExtHelper ORDER BY ExtHelperValue;
If the PK for the combo field is ExtHelperID then when I look at your table, that field has 7 values all the same (1). That doesn't seem right. A combo value (when the bound column is the first column) should be going in to the PK field of the related record. I suppose that Access will store the value in the table field for you, but when it's bound column has 7 values, it doesn't know which one to show you. If that's not it, I am stumped for the moment. Regardless, I will offer that it's unusual to bind a combo to a field that can contain multiple values that are the same. In fact, it's not something I'd think to do.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.