An International Monetary Fund technical team is in Luanda this week seeking to mend years of problematic relations with Angola. But as fresh signs of rapprochement emerge, a new chapter has opened in a murky saga involving debt deals with Russia, long a stumbling block in the country's relations with the IMF. A rapidly expanding offshore oil industry and abundant other resources make Angola one of Africa's brightest prospects. But the economy has been undermined by decades of civil war and corruption.