I'm, after a bit of clarification on service monitors assigned to system groups. When a service monitor is created for a system group then you have the parent (for want of a better term) version and then all the child versions which all have '(member)' attached to their names.
I know that to change an individual you have to detach it, and it then becomes stand-alone. But when the parent is changed none of the current child ones are (though I guess new additions to the group would inherit the new parent settings).
I would have thought that any change to the parent would be passed down to all the children that are still attached. The reason I bring this up is that to change multiple service monitors assigned to a group (and still attached) I have to detach each one and change (then they're all stand alone) or I guess I have to do some database editing and I'd rather avoid that sort of thing if possible.