Re: "Touch" Calc Problem

I think I would go at it another way...

1. Add a Copy Rule to the object (e.g., Note).
2. Have it fire only on the Create event.
3. Set 'Target' equal to your custom field (i.e., [_CurrentOwner])
4. Set 'Source' to [Incident/LatestAssignment/User/Title]
   (with a possible secondary source of [Incident/LatestAssignment/Group/Title] in case it's not individually assigned, if you really want to capture that)

I would actually take it one step further and make your custom field (_CurrentOwner) a reference to User instead of a string value, and then just use [Incident/LatestAssignment/User] as your Source.  Names change, but {Guid}'s are forever...

Later on, you can report on these objects just by counting those where [(object)/_CurrentOwner] != [(object)/CreatedBy]

-Brian