Setting DefaultStack to TopStack does not make it's stack script available?

[Brahmanathaswami]

7.1 rc(1)

I am trying to create some tools that can be used across many stacks. in 
some cases it's not completely generic and I want to have functions 
unique to scripts in the topstack to "fire"

e.g.

stack 1 : utilities.livecode # set to palette mode

stack 2: topstack: myProject.livecode

in Stack 1 we have this button:

on mouseUp
    set the defaultstack to the topstack
    put the htmltext of fld "textcontent" into url ( "file://" & 
localPath() & "data/about-this-app.html")
end mouseUp

But I'm getting an error because Stack 1 (in palette mode) cannot find 
the function "localPath()"

Is this a bug... I could have sworn before that if you set the 
defaultStack to the topstack then all it's scripts became part off of 
the message path. But not today...

BR