My Dyson DC07 is several years old and works really well with very good suction but recently when I hoover it won't pick up small pieces of fluff such as sock fluff from the carpet. I regularly give it a good clean and clean the filters and it pulls at the carpet when hoovering but still the fluff remains. Any ideas please?

You need to disassemble it enough to get to the blower, for one thing. Then clean it really well because 1/16" of dirt will cause a 30% drop in airflow. Then you need to check the parts of the beater wheel at the nozzle. Clean out that very well and make sure it's clear and that nothing is broken causing an air leak.