" I spent a fortune on the bomb things, and the carpet hoover stuff and the flea furniture spray. thought they would all be gone but im finding a few again"
The flea-treatment you used on the kitten and the house-spray might be working but what none of these preparations can do is kill the pupae lurking in the carpets and furnishings and they can survive for months and months. They will eventuall hatch and jump up on your cat but if you're using an effective preparation like Frontline they will be unable to breed before they die. The best thing to do to encourage the pupae to hatch is to vacuum, vacuum, vacuum; that way you will pick up eggs and larvae as well as the newly emerged adult fleas. Put a cut-up flea collar or flea-spray on a J-Cloth into the hoover-bag and dispose of the hoover-bag every time you use the cleaner.