According to Erich Hartmann's bio he (Hartmann) would attack IL-2s from a low 6 position and concentrate his fire on the oil-cooler. According to him that was the most vulnerable part of the plane and (for a good shot and from a very close distance) the best way to quickly down a Sturmovik.
In this bio the Sturmovik is also credited with being the toughest bird on the eastern front. Some german pilots claimed that they saw their 20mmm shells bouncing off IL-2s.
BTW: The new release date for IL-2 is November 2001

Sascha
------------------
Jagdgeschwader 77 "Herz As!"
[This message has been edited by Sascha JG 77 (edited 05-14-2001).]