Flywheel noise?
 

A few weeks ago i put in a new clutch and lightweight flywheel, as well as pilot and throw out bearings.
just recently when i was driving home from work, 35km drive, when i got in town i noticed a hum or whine that increased or decreased with RPM, doenst matter what gear clutch in or out.
Also it wont happen till ive driven for a bit, if i go and start up my car right now it wont be there but by the time i get to work it will be.
Im thinking it's the flywheel but, ive also read the lightweight flywheels will trasmit engine/tranny nosie.
anyone have this happen before, or got any ideas???