Just ran into a rather unpleasant bug with the 2.0 edition of GOG Witcher 2.
Playing with an imported save where I picked the Neutral path and talked Siegfried out of the fight in the streets of Vizima (meaning he remained alive), I still had the "angry Flaming Rose knight fight" encounter when on Roche path. Bummer. 66.234.47.205 00:41, October 7, 2011 (UTC)