They just stopped working! I have 2 vacuums one is approx 6 months old and the other 1 1/2 years

Question

I have 2 vacuums one is approx 6 months old and the other 1 1/2 years old. The model numbers respectively are:
U5194-900 series: ZF12.0 quit 3 weeks ago
and
U5180-900 series: ZC12.0 quit today (1/6/2008)

I was vacuuming a light job on carpet and they just quit working. The motors on both did the same thing. They just stopped turning. I checked to see if there was something keeping it from moving and they both could easily turn freely from the beater bar and at the motor shaft. I checked the breaker and it was not tripped. The push switch clicks as if it works. Any ideas and could this be taken care of under warrenty? I doubt that I kept the receipts, thinking that Hoover was a very good quality product.