Visible of stack is false - but still visible - why?

[Doug Lerner]

I can check and uncheck the Visible of a stack, but it remains visible.
(Other stacks don't experience this problem.)

In the message window I can also do

set the visible of stack "thisStack" to true
or
set the visible of stack "thisStack" to false

and when I look at the Visible value in the stack inspector the value looks
correct, like I set it.

But the stack remains visible regardless.

Any idea what might cause this behavior?

Thanks,

doug