Juba, South Sudan
There are serious concerns about relations with the region's old rulers in Khartoum in the north and about ongoing fighting in the Nuba Mountains in the south.
And some of those at the centre of the battle for independence already fear it may not deliver all that was hoped.
Lt Peter Bol Deng stared at me for a while, and then announced quietly that we had met before.
Cattle remain vital to South Sudan's economy and were a wartime target
I had come to meet his boss, the now legendary rebel leader John Garang, and he was then one of Garang's soldiers, but also well known for his songs, encouraging the rebellion in South Sudan in which mostly black and Christian southerners were fighting mostly Muslim northerners.
To be honest, I do not remember meeting Bol Deng then - but he did not sing to me on that occasion.
I do of course remember talking to Garang out in the bush, surrounded by his fighters.
We had just been filming units of the SPLA (Sudan People's Liberation Army) guerrillas fighting off a furious attack by Sudanese forces to the south of Juba.
Garang told me they were determined to defend the south from the imposition of Sharia law.
Today, it is all very different. Juba is now the capital of the newly independent South Sudan, where Garang is buried in a grand mausoleum, guarded by soldiers and surrounded by flags. He died in a helicopter crash just over six years ago.
And as for Lt Bol Deng, he was still singing, he was still in the army, but he was worried that the independence he fought for has not brought the changes he expected.
When I met him this time round he was sitting outside his mud and thatch hut on the outskirts of Juba, a tall, thin figure still wearing an SPLA cap.
John Garang is buried in a grand mausoleum under guard
He clearly enjoyed singing, and still had a powerful voice, but seemed far less happy when talking about present day Juba.
Of course he was delighted by independence, but he complained that there was corruption, people were not getting the resources they had been promised, everyone was out for themselves and the wartime spirit had gone.
And then there was the question of cattle.
Like all Dinka, and many other groups in South Sudan, Bol Deng adores cattle, which are seen as a symbol and source of wealth and have an almost mystical importance.
I wanted to visit a cattle camp, and hear him singing cattle songs, which are often highly personal, can deal with a family history or the history of a nation, and are performed to a favourite cow or ox before being sung to the community, or recorded on cassettes to be distributed to family members.
It was not that easy. The owners of the cattle were at first suspicious of letting us near their cows.
"Would you just walk into a bank and take pictures of people's money?" asked the owner of one large herd of several hundred magnificent white long-horned cattle.
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It was no surprise, then, that during the war the Sudanese deliberately bombed southern cattle camps, killing thousands of cattle, and that one of the major problems facing the new nation was cattle-stealing.
Gangs of heavily-armed raiders attack cattle camps, and in some parts of the country like Jonglei state they have stolen hundreds of thousands of cattle, and killed thousands of people.
The new government blames Khartoum for providing the weapons, and says the aim is to de-stabilise the new South Sudan.
The government wants to end cattle dowry payments
Even if this means that the traditional cattle songs die out in the process.
The idea horrified Bol Deng. When we were eventually given permission to enter the cattle camp, he tracked down his favourite ox - a rather fine black and white beast by the name of Makuei and began to sing to him.
In the lengthy song he advised the ox that when he was given in dowry, he should only be handed over in exchange for a woman who was likely to remain faithful, not one who moved from house to house like a cat.
Across the camp, I could see other men also singing and the much-pampered cattle seemed to enjoy it.
So what did Bol Deng think about the government plans for commercial ranching, and an end to the old traditions?
"This is our identity," he said. "This is what we fought for. Now we are independent and the government can't take this away."
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