Hi Zoran ,
Many thanks for the response - yes it answers my problem. Though you might want to enhance the article just a bit to show how the code originally looked (before the changes).
I did spend some time searching the support site looking for this - since it seemed obvious that I coudl not be the first person to need the solution. I tried quite a few combinations of OpenAccess, GridDropDownColumn and the error message, but the only thread I could find that seemed relevant was Forum Article
which I found to be rather incomplete (and actually a little misleading - have a look at the code posted ).
Do you have any idea when this might become part of OA - I ask partly because I note that some of the code gets lost when the Reverse Mapping wizard is used to update the Object Model - and since my project is under heavy development I will be having to use it quite a bit - and also because I woudl like to get access to the "DataBase" reference values for some of my reporting intentions (and preferably not by having to go via the referenceed object - in my case the database reference is sufficient for most filtering and display purposes since the key value is also the name/text value).
P.S. I am still impressed with the speed with which you answer question like this.