presumably you have set the mode to passive. that's always step1. error 553 usually
signals a permissions issue. it could also indicate a file name problem. assume it's
a permissions matter and go from there. basically, do you have permission to write to
the folder in question? (and do you have permission to cross folders to get to the one
you're looking for?) also, if you were replacing a file, what were its permissions? are yours
bigger?
i don't know who's running the server, so i can't say how difficult it will be for you to
learn what your permissions are. tell the administrator you got a 553. if the administrator
is you, get out your manual.
ascii, binary, writebytes, etc would not cause a 553 (unless the server was poorly configured).