When there's a space in a variable (or any other non-numeric character) mIRC treats that variable as text and so does a text comparison for "4" and " 5". " 5" is less than "4" for a text comparison (the ASCII code for "4" is 52), so the loop fails to execute. The parser ignores literal spaces in the code but will take into account spaces evaluated from identifiers/variables. This is the correct behaviour and it'd be very frustrating if it didn't work like that.
