We can also add code to LyX 1.6 that reads these borked files: if MyStyle does not exist and the inset is of type Custom, try Custom:MyStyle.
Of course, we do not know that the inset is of type custom... So, wewould have to try in turn CharStyle:MyStyle, Element:MyStyle and Custom:MyStyle.
Not very nice. And people have to have the latest 1.6 version. JMarc