Seems more down to a wandering default font index on the font and its disassociation from the lineGrid baseline and leading on TextStyle to me...
It is very annoying though.

> >  >
> >  >
> >
> > When we are at it we should fix the issue that happen when you delete
> >  all chars from a text and the caret get a smaller size and change the
> >  font !!! Very annoying !
> >
> 
> Yes, it's because the height of caret should depend on a character
> which its standing upon.
> I can't find an easy way to determine character properties at current
> caret position (or any position in text), so i given up with changing
> shape.
> These paragraph/textmorph are complex beasts :)
>