I have tried to simulate somewhat similar behavior here - http://dojo.telerik.com/oNAyi/2. I have also attached the sample code in case if the link doesn't work.
If there is atleast 1 locked column and if the grid is not displayed on page load, (in this case grid is displayed on click of a button), then the UI is totally disrupted. Also, as the
number of columns increases, the non-editable column is no longer displayed.
is not exactly what I’m facing, but similar. In my case, entire grid width is occupied by the locked and non-editable columns and all editable & unlocked columns are crunched on the right. The header displays column name of the first non-editable & unlocked column.