Arduino doesn't work when restart [SOLVE]

Hello.I am doing various tests to my project Arduino+GSM Shield+Sensor.This is the workflow of it:

1-Power apply to the prototype
2-After 2 minutes,GSM Shield send data from a sensor to pachube(xively) platform.
3-Every 30 minutes send data from sensor.
4-Disconnection from power source after 8 hours.
5-After 12 hours aprox. from disconnection, restart power to the prototype(Arduino+GSM+Sensor same time).
Problem:
** It doesn't connect to xively and not send data.

The code in Arduino resets after x hours?
Thank very much.

patricio_74:
The code in Arduino resets after x hours?

No.

Its hard to see how to help when you haven't provided any of the
necessary information, such as the code... The sticky thread explaining
how to post here is there for a reason, suggest you consult it.

Thanks for your reply.I was not sure if the code reset after x hours/days.
I have changed the GSM Shield position and the coverage is better so now sends data corretly.

Thank you very much.