The victim of two Sharks.

I can't be the only one! I bought a Shark Navigator, a cordless vacuum cleaner. The first two times it worked liked charm. I maintained it exactly as they said. Then, like a recalcitrant spouse, it refused to pick up even the smallest pieces of paper no matter how many times I went back and forth. I called the company. They insisted that was odd, and allowed me to buy a second machine for only $35.00 (they should have given it to me). Lo and behold the new Navigator picked up everything, proudly displayed a chamber full of dust bunnies, string, paper, dirt. Obviously the first one was a dud. But wait. By the third use of this well-maintained machine, the same thing. It refuses to pick up anything. I just finished a messy product with lots of litter on the rug. The Shark refused to behave. Finally I had to consign it to the closet and take out the $12.00 Bissell carpet sweeper which picked up everything in a flash. Can I really be the only person in America who is having trouble with the Shark Navigator?