My situation is : I have a custom dialog box and edit box control on it (enabled and visible, so, user can type in this edit box). The property connected to this edit box is _PROP. Also I have a push button, that activates the custom action, where I change the value of _PROP. In the behaviour tab of my push button I use the following rows for refresh edit box content :
DoAction CustomActionName 1
[_PROP] [_PROP] 1
My problem is : this approach works fine, but only in situation, when user did not type any characters in edit box... If I type even space bar, and, after that, activate my custom action and change property _PROP, my edit box does not refresh

It seems as next bug of Win Installer... Isn't it?
Thanks in advance for your help.
Michael