I'm pretty sure this question has been asked several times, but i'm quite new at adobe live cycle and i'm already having an issue. I feel as if it's a really simple issue...?
I believe the SOM Expression you're using are just wrong because you use this.resolveNode which will start a search for nodes only in the subtree of the XML source beginning with the current node (Checkbox1).
As there are no nodes below TopmostSubform.Page1.Table.Row.Cell.Paragraph.Checkbox1 resolveable and so nothing happens.
You screenshot doesn't show the hierarchy of this part of the form, so I cannot say, which will be the correct SOM expression for you to use.
Ive tried that already. I figured out a different way to implement the unchecks though, via right click @ checkbox and using the actions list. now im just wondering if there is a faster way to implement these lines of codes manually without using the actions list.