Hi,
Playing the Jan 1805 campaign as France; defeated Austria with no real issues and took the Peace of Pressburg in Oct 1805. Austria declared war on Bavaria, which has a full alliance with France (has had since first turn - Austria declared war on Bavaria turn 3 which started the war real early ...), six weeks after Pressburg in early Dec 1805 .....! Shouldn't Austria be at peace with France and its alliance members for a period! and surely the AI recognises that declaring war on a Minor in alliance means war with the Major nation? This does not make any sense and needs to be looked at. For your consideration.
Cheers,
AKL