Well from taking a look at their site, whether or not the recording is true, they certainly look like a completely legitimate online African daily.
Let’s face it no one is going to make up a website with 1000’s of articles just to perpetuate one fraud.
Let me give you an example.
If you go to http://africanpress.wordpress.com/2008/02/
You will see a byline by Leo Odera Omolo in Kisumu. (I picked this totally at random)
A google news search that name pointed me to an article in the Boston globe about Obama’s father which reads in part:
“Although Obama had always enjoyed his beer, he was developing a taste for Johnnie Walker Black that earned him the nickname ‘Mr. Double Double.’ After Obama ordered his customary double Scotch, “He would shout in that big deep voice, ‘Waiter, another double!’ said Leo Odera Omolo, a journalist and drinking buddy of Obama’s, who lives in Kisumu, a port city in Kenya.”
So low and behold. He is really a journalist and in Kisumu a port city of Kenya.
Since they have a lot of correspondants in Kenya, some of whom even KNEW the family she probably felt completely comfortable. Furthermore, to me it looks like they had the connections to be granted such an interview!