here is how you delete a photo from a note (assuming you have SN v1.1): 1.) double tap on the note that has a photo attached to it 2.) you will see the picture for that note. 3.) at the bottom left there is a trashcan 4.) tap on the trashcan - and it will remove the photo from the note (it will not delete the note)
just to give you a quick update on this bug - I've slated this for our next v1.7 release. I have submitted v1.6 last week to apple - and hope that they will approve it within a week. And currently, my dev team is working on v1.7 - which I've put into the backlog.