Hi,
I don't think we can use triggers as this is an optional function.
We are already copying the HTML description field to a plain text one on Save using a calculation to strip out tags.
At first we suspected this was teh problem, but removing it makes no odds. Nor does taking away restrictions (write once) on teh window.
As you can see from the attached vid, the field clears just before saving, but only on the main HTML field. In fact if we set this to mandatory it won't let us save so the field is clearing before the checks kick in.
Cheers - Adam.