...And connected Rx (pin 0 duemilanove w/o atmega) to Rx (PD2 to atmega) and Tx (pin 1 duemilanove w/o atmega) to Tx (PD1 to atmega) .
Have another look to confirm you actually did wire up like this.
If you did, then this is where your error is.
I can't tell whether the functions of the pins are as you stated in your implementation of software serial (and i don't understand why you need to do this, but that aside).
But you are saying you connected the receive to receive and transmit to transmit.
How do you think you will receive any signal that is not transmitted (because a receiver doesn't transmit) ?
By the way, there is something missing in your schematics.
Where is the second controller ?
And where is the connection we are trying to debug at the moment ?
An outgoing arrow with a label is not a connection if there is no incoming arrow that has the same label.
As for this, i can see something (to my taste incorrect drawn) that looks like a connection, on that right side going to your GSM.
Which means it can't go to some other device.
Show us a new drawing or a clear photograph where you show how you have wired up your setup (so not how you are supposed to wire it, but how it is actually wired).