Thanks Nancy for sticking around for details.
1. Yes the fields are all marked updateable.
2. It's a simple character field called DESC that holds the description for the code it represents. It's not the PK or costcode.typeid. This field hold no special value, no relation to any other table or anything else.
3. Yes, I could use/view the View but can't change the data in this particular field. It happens when I edit it and try to move away from the field (tab, enter, arrow keys, etc.) It seems like there some sort of validation taking place but I haven't defined any! Like I said, if I just open the table itself and edit the data in this field, I have no problem. Again, very strange.

>Maybe it's just me, but a couple of things still aren't clear to me.
>
>1. Have you confirmed that the field is in fact set as updateable (probably, I'm sure)
>
>2. _Which_ field is the problem? costcode.typeid? Is it a primary key? If not, then what is the field that breaks?
>
>3. Do you browse the view and try to make edits and get the error? So you can USE the view okay, but not change the field? Does the error happen when you tab out of the field? Or into it?