Courtesy of Regret the Error:

A map showing the spread of bird flu in Europe (pages 4 and 5, April 8) accidentally included Yugoslavia, which is no more. It should have shown Croatia, Serbia and Montenegro, Bosnia and Herzegovina, Macedonia, and Slovenia. Belgrade, the capital of Serbia, was similarly anachronistically described as Yugoslavia's capital in Weatherwatch, page 33, April 4. Link

That's OK, I can't keep track of the Balkans, either.