Zealous 'file format' save notifications

[Ben Rubinstein]

I recently started working with a file from 6.7.11 in 8.1.1.  Having carefully 
set the file format preservation, so that I can continue to work with it back 
and forth between 6.7.11 and 8.1.1, I now get this message each time I save:

	The preference to preserve stack file formats is set,
	however, saving this stack file as version 5.5 will
	result in data loss. The minimum stack file version
	for this stack is 7.0.

Since the stack came directly from LC 6, this seems implausible.

On further investigation I see that there is a new property, the 
minStackFileVersion. "The minStackFileVersion property is read only and 
determined by the content of the stack file.", according to the dictionary.

Well, that sounds good. But then I read "The minimum stack version reported by 
the property is 7.0.".

How can this be helpful? And if that is how the property is defined, wouldn't 
it better if saving didn't throw up the above dialog when minStackFileVersion 
= 7.0, since that should in fact be taken as "not sure" or "doesn't need 8.0".

Is there a subtlety here that I'm missing?

Ben