>>_Access and _Assign were added later. Since we got them, we may use them with any properties we want, as VFP documentation clearly states that:
>
>But is using the user interface the same as explicitly setting a properties value? I don't think so.

It appears there is some difference. That is the quirk exactly :) because it is not consistent for all native properties. The docs don't say anything (at least I couldn't find) about the way the property is changed or how it can affect the result.