Undefined GLOBAL label error on array (solved)

[short_jonny]

Hi,
Recently started experimented with the compiler. It's been great so far but I've just started getting unexpected errors using arrays. Compiling the snippet below results in:
test.bas:55: error: Undefined GLOBAL label '._myArray'.  
I can't see why this is failing ?  Am I doing something stupid ?  
I've used 1.14.1 and the latest state of the repo. Is it a bug ?

DIM myArray(1 to 6) as ubyte

SUB Init(byval num as ubyte)
    DIM i as ubyte
    FOR i=1 TO num
        myArray(i) = 0
    NEXT i
END SUB

Init(6)


Jonathan