Passing an array overlay as a parameter

My question is pretty much entirely in the link.  I've copied it below.
http://code.midrange.com/index.php?id=da5285b59e
 
I was trying to see how this function key setup would work using
Overlays (was previously defined in a compile-time array).
 
In the program, when I display FKy#FKy, it properly shows me an array of
text, and not the switches.
When I display FKy#Swtch, it properly shows me an array of switches, and
no text.
 
When I step into the $LoadKeys procedure, though, and I see what the
values of those arrays are, the FKy#FKy array includes the switches.
The FKy#Swtch array evaluates to "1F2=Continue    ".
 
If I move the arrays into intermediate arrays, which I then pass to the
procedure, then it works. 

Why is it passing a value to the procedure that is different than what I
see in the program when I'm in debug (Optimize *None). 
 
Thanks,
 
Kurt Anderson
Application Developer
Highsmith Inc.
W5527 State Road 106, P.O. Box 800
Fort Atkinson, WI 53538-0800
TEL (920) 563-9571  FAX (920) 563-7395
EMAIL kjanderson@xxxxxxxxxxxxx