It can't be acting as a supernode if it is turned off as the OP has mentioned a few times in the thread...
EDIT: That is assuming it is the laptop that is switched off - but then earlier the OP did say that they hadn't woken the laptop from sleep so assuming skype can't work on a sleeping computer then essentially the laptop would have been off and not using bandwidth.
Edited by ian72 (Fri 05-Mar-10 15:48:55)