I guess that depends on just which cable it is...
If it's a 'dongle' type cable (ie where the cable takes care of the software activation itself) it's obviously more valuable because the latest software will work - you're not a registered user though, and therefore not eligable for technical support or trade-in offers.
If it's a 'dumb' cable (where you have to type in activation codes), you're required to buy a completely new licence for the software...
Full explanation available at: http://www.ross-tech.com/vag-com/faq_3.html#3.10
Out of interest, what cable is it?
Rob.
A4 B5 1.8TQS Avant - Lightened fuel tank, two fantastic wheel bearings - two more an unknown quantity, boot full of lenses.