I have been using this.presence = "hidden" on the initialize event of the subform in question.
All works fine, until I extend features for Reader using Acrobat Pro. After that point, when the form is opened in Reader without JS enabled, the subform is not visible - which is strange, as surely JS would have to be on in order for that subform to dissapear.
Something along these lines has been discussed before. When the form is Reader Enabled in Acrobat and then subsequently opened, the initialized event (and I am sure the layout:ready event) fire twice. See at least one discussion here: http://forums.adobe.com/message/3028586#3028586 and the form here: http://assure.ly/gW3RNr.
Try the docReady event.
Thanks for your response. It's your kind suggestion from a while back in case you remember!
docReady seems to have the same issue in this context also - very frustraiting! Any thoughts on a workaround? It's beyond me!