Note I will hardly ever test if I'm not sure we're talking about the same BS.Player builds!
Anyhow, meanwhile tested (using
this rar-archive, which I renamed to .avi); BS.Player simply opens a window "Unraring..." mentioning which media-files it unpacks and then starts playing them.
So ... I cannot confirm. (Win XP SP3 - BS.Player Pro version 2.51 build 1022, 26 dec 2009)