On 18/09/2010 10:00, Frank Mittelbach wrote:
> Option names have no spaces and no braces and so the result of passing such
> stuff is undefined (well not undefined as the behavior is deterministic, but
> there can be "surprising" behaviour for boundary cases). So the result of
> undefined usage doesn't classify as a bug.

Okay, I'll note for future reference that this may or may not work. In 
siunitx v2 I have tried to make all of the options work after load time 
(in \sisetup) partly to avoid the limitations of the optional argument 
to \usepackage.
-- 
Joseph Wright