This is a weird one.
I have a continuous form that is fully editable. However from the second record onwards it is non-editable. As in, Access does not even report that it is locked or anything. I click and there is no response even though the putting the mouse over the text field makes the cursor a text cursor.
Hope this makes sense and someone has experienced this before
Very stupid microsoft solution sometimes works with very weird problems:
create a new Form, copy all controls to the new form, you might have to reassign the forms datasource and try if it is still there.
Right now it is one of the big Access mysteries and I would have to see the database to know what's wrong. (I have access to Access 2000 and Access 97)