Changes to text procedures

We have created our own text procedure(Z1) for sales documents in VOTXN which contained a number of text types.

Then tried to remove some of the text types but keeping the same text procedure id

What I found was that even though the text types no longer exist when you check the sales document you still see an entry for the deleted text type with out any description.

I can only assume that the even though the text types have been deleted they still exists somewhere against the text procedure Z1

Has anyone come across this issue before.