kb891781 (problem with dhtmled.ocx)

Hi,
today I've installed latest security update kb891781, which caused, that our
application for web content management that uses MSHTML editing ActiveX
control dhtmled.ocx, stops work. Our application is developed in Delphi and
uses this component for content managing.
I found the problem (after tracing some debug info)- the application
couldn't get access to the DOM (IHtmlEditDocument2 interface) through
IHTMLEdit interface, so it raised the exception "Unknown interface".
I didn't find any workaround than uninstall this security fix. Then
everything was OK as before. Of course, I spent some time with security
settings in IE - I enabled almost everything, but nothing helped.

I tried to find whether some other has the same problem and I found some
polish application based on this component having the same trouble.

Does anybody has any idea where the problem is?
Thanx.