combobox run-time error 381 could not get column property. Invalid property array index

[davidmyers]

Hi I have a combobox with 2 columns - 1st column is bound, when I begin to enter a term it jumps to the right place in the list (sorted alphabetically) if i select a term from the list all's ok.The problem is when I try and to exit the combobox or enter a term that's not on the list I get the run-time error 381 with the message in the title.
I have a second combobox with 1 column and there's no problem with that I can select, delete the selected item (backspace) or exit. both comboboxes use a range defined in the Name Manager

Any suggestions how to solve this?

Thanks
David