Hooking up a gas & smoke (MQ-2) sensor

Hi,
I am also using MQ 6 sensor. I interfaced it with ardunio uno 328 board. Its working fine as i done the same connections as given in that http://www.thaieasyelec.com/Sensors.

I want to connect temperature sensor also. i am using LM35. it is also working fine.

But both work when i connect them individually.

When i try to connect both simultaneously on A0 and A1, values from both sensor get disturbed.
Why?