Description contents cannot be deleted

I have a very odd situation where the contents of the Description field for Product cannot be deleted. I can even go to the “Text” tab, delete everything and then save – and the text magically re-appears.

I even went so far as to delete the item and when I add it again under the same name, the old text is in the Description field even though I left it empty.

Can someone please have a look at this behaviour.

Many thanks!

Edward