Xbee startup problem

Today I received my first 2 xBee's.
I tried to configure them using my Arduino but I can not seem to find out.

I am using a custom board that has a voltage regulator and connects to the 5v, GND, RX and TX of the Arduino. I am 100% sure the board is working correctly.

I connected the xBee to USB using the standard programmer (I don't know what it is called but it only contains the FTDI chip). I can make a connection in X-CTU.

Since my Arduino also has this FTDI chip I thought it would be possible to change the configuration with my Arduino too. I removed the atmel from the board and connected the xBee with the arduino. When I measure the voltage is correct. I can however not establish a connection in X-CTU (unable to connect). Can anybody tell me what I am doing wrong?

On the XBee shield you need to change the positions of the jumpers for that to work.

On your "custom" board, you need to swap the M8RXD and M8TXD signals.

Thanks it worked!