I had the same problem. There is a thread on here somewhere describing all the things I did to try to get the code.
In the end I went to the following website:
http://www.radio-code.co.uk/
I sent them £10 and the Becker code (as I was worried it was a scam and did not want to give them my credit card details on-line).
The next day they e-mailed me the 4 digit code which worked fine.
I hope you have the same solution.
Chris