SetStatusWindow text overlays existing text

[SirAthos]

During installation, if a dialog is displayed before actually installing, the status text display portion may start overlaying new status messages over the existing message (instead of erasing the existing status message first). As a result, the status message is not readable anymore.

This bug is persisting since v7 of InstallShield. :mad: I just upgraded from IS2009 to IS2012, hoping that the bug would be gone... to no avail.
Here is a thread that describes the same problem, posted more than 8 years ago.

Attaching an image that shows the problem.

[SirAthos]

Code to reproduce the problem:

function OnFirstUIBefore()
    STRING szText;
    // ...
begin
    // ...
    Enable(STATUSEX);

    szText = "";
    SdShowDlgEdit1("Custom dialog", "Click Next to break the status messages.", "Blah:", szText);

    Enable(STATUSEX);
    return 0;
end;

Any status messages shown after the custom dialog (such as "Copying files", etc) will garble the display.