BV4111 and Raspberry Pi

I connected everything like the website says, but when i launch the Demo project i receive this message:
Error can'initialise, try again

even though the cables are connected in the same way the 1st time they worked.
Maybe my software configuration is wrong

With the RPi switched on, disconnect the BV4111 and then connect it up again.
Check that you have got TX connected to RX and RX connected to TX and that the ground is still in place. Now run the demo.
I am using an old version of 2012-09-18-wheezy-raspbian but that should not effect the serial port. If you have had it working then I would re-check the wiring.

I've tried it with two different versions of raspbian, and they send me the same error.

If it's still not working, is it possible to send back only the bv4111. The relay board works properly
I'm an Italian customer, what's the easier and the cheaper way to send it back in the UK?

You can send just the board back by normal post but it may save you time by investigating other avenues and assuming the bv4111 is working okay. I say this because of all of the items I have got back, so far 100% turned out to be something else and there has been nothing wrong with the item sent back. If the board is faulty I will of course send you another and refund your postage.

Here are some pointers:
1) do a factory reset of the bv4111
2) can you check the serial communication is working on the RPi with some other device?
3) are any of the 4 wires going from the RPi to the BV4111 broken?
4) download the demo software again
5) have you a terminal and a USB to serial device so you can check the BV4111 away from the RPi?

- jimeer

Problem solved, i have to unplug the wires every time i reboot my system. It seems to be a plug-and-play hardware
Thank you for help, you solved my problem and i save a lot of GPIOs