I've tried rebuilding the grid from scratch and I get the same result. As you suggested, I tried leaving all of the read-only properties for the grid and each of its columns set to their default (.F.) and it still will not let me write to the cursor!

Just before I link the grid to the cursor, I'm inserting about 110 records into it. What else could I be doing wrong in creating the cursor that it won't let me edit the values via the grid?