Document.Modified and LineModificationMarkingEnabled

Hi,

It seems that DocumentModifiedChanged event is not fired correctly after changing of Document.LineModificationMarkingEnabled property.

In TestApplication (SDI Editor) :

1. Start SDI Editor. Uncheck menu item "Edit->Mark Line Modifications".
2. Check menu item "Edit->Mark Line Modifications" again.
3. Print some text. In Event tab I see "DocumentModifiedChanged: Modified=True" - ok.
4. Undo all printing operations, but I do not see "DocumentModifiedChanged: Modified=False" in the Event tab and property Document.Modified is true.

Is it a bug?

Thanks,
Nik