Simple example with XBee series 2 doesn't work?

Currently I'm trying out some XBee series 2 shields for Arduino and I want to run the Simple Example between them. However, while the programs compile perfectly and seem to do their job (when viewed and simulated with the Serial Monitor) the XBee don't seem to communicate with each other. When left alone, nothing happens.

Odd thing is, when I connected to XBee series 1 shields to the same Arduino's, the example works.

So are there any configuration differences I need to know about? I already tried looking into the XBee series 2 configuration, but I couldn't find anything that indicated why the serial communication between them wouldn't work. I can't seem to find the API mode setting though.

Any ideas on the difference?

series 1 will work out of the box, because they are point to point.
series 2 are mesh , so need a liitle more configing .

Read this :-

http://www.humboldt.edu/~cm19/XBee%20setup.pdf

or this :-

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1204645075/5