Zodiac had some confusing model name changes during the 2000's.
I have a 2002 brochure and then there was the Fastroller which was an air floor with similar sausage keel to the hard floor models.... no Lightroller.
Then at some time they changed the name of that design to the Lightroller (there may have been other changes too).
Here is a 2005 one for sale in Ireland...
Zodiac Cadet 340 LightRoller - Punts/Tenders - Boat For Sale Ads, Boats For Sale Ireland, Buy & Sell New & Used
I guess about the same time then the Fastroller was reintroduced with the HP keel linked to the air floor and became the acti-V.