[ic] on-the-fly item weight

[sphen]

hey everyone...

im using the on-the-fly product ability of interchange to order a few 
parts in our shopping cart.  The only problem is that there is no 
documentation on how to specify the weight of an onfly item... only the 
description and price?

my tag looks something like:
$Tag->area( { href => "process",								form => "mv_todo=refresh
		mv_order_item=$part
		mv_order_fly=price=$price|description=$desc|weight=$weight" } );

I tried adding the weight part as shown, but it doesnt do anything?

I need to figure this out because people ordering those parts now get 
free shipping :-\  hmm..

Thanks!

-sphen