Everything is in the Title.
The DefaultZcript got called again (first time for startup as expected) when I toggle the Zscript:Hide Zcript button (e.g "H").
As it stands your code will run everytime. Change it so that it only runs when the memblock doesn't exist:
[CODE]
[If,[MemGetSize,StartupMem],
//do nothing
,//else no memblock
[RoutineCall, setup]
[MVarDef,StartupMem,1]
][/CODE]