Edit Album Tags Directly

Why is it not possible to edit extended 'Album' tags directly by clicking on the field box?
Double click on 'Title' for instance, allows the content to be edited, but double click on 'Album' and it automatically plays the track as if it is an un-editable tag such as 'BitRate'.
Is this a bug?

Where do you double-click?
In the files list?
Then check the column definition and see that
Value & Field
both show %album%