Setting property from within custom action does not refresh controls

Hello,

if on the dialog I change the value of a property directly, such as by edit
field, or by event SetProperty linked to a button, then other controls on
this dialog sourced from this property show the new value immediately, and
buttons with conditions depending on this property change their state
immediately (for example, to enable/disable button "next"). But if I set the
property from within custom action, for instance from vbscript using Session
object, then other controls are not refreshed. Is there a way to "push" the
refresh from within custom action?

To reproduce:

In the installation, create property MYPROPERTY with the initial value 0.

On a dialog, put button 1, and specify event [MYPROPERTY] with argument 1
Put another button that publishes DoAction, action type 38 being vbscript

Session.Property("MYPROPERTY") = 1

On the same dialog, create textbox with its text being [MYPROPERTY].

Press button1, and the textbox immediately changes from 0 to 1. Press button
2, and the textbox does not change - though if you go to the next dialog and
then return, it will show 1.

thanks,
Vadim Rapp