Hi Peter, I use extern all the time, so I think it is caused by something else.
Does this work in isolation for you?
Extern STDCALL Lib "kernel32.dll"
! GetModuleHandleA
! Sleep
! GetTickCount
! ReadFile
! WriteFile
! CloseHandle
! CreateFileA
! GetFileSize
End Extern
'#recordof GetModuleHandleA
sleep 1000
print hex GetModuleHandleA