I've read about putting a pull up resistor with a min of 4.7K and a max of 10K Ohm between the VCC and Data pin to make sure the readings will be correct.
Then I've also read that it could have to do with the voltage being too low. You could try supplying it with 5V instead of 3.3V, as 3.3V is the minimum given by the datasheets, but there have been reports that this is not high enough.
I want to apologize if this answer doesn't help you or if I'm totally wrong about this, but I hope it might help someone.
Lenard