To be honest, Ive only encountered a single bug.
You're not just looking hard enough into it. Though, I've only had one crash and that forced me to boot the computer because I couldn't refresh the screen anymore - that makes this game one of the most stable releases out of the box in a long time.
but some bugs that I can remember in couple of seconds:
1) troops are having difficulty moving through the gates - fleeing troops may get stuck at the gate and keep it open and there's nothing you can do about it.
2) if you have two pieces of foot artillery/howitzers and you tell the other to hook up, it will do that, but with the other you have to click the button twice to get the piece to hook up.
3) when you tell artillery pieces to stop firing at will they will still blaze away, usually at nothing. This "feature" has killed quite a few friendly troops so far. Not to mention that the gunners are brainless morons that have to be pampered all the time - they don't care if there's a line across their position.
4) when attemping to move agents from towns with troops you might end up moving a troop instead.
5) troops will not fire at a fleeing infantry that has separated from it's "flag troop", and sometimes the soldiers of a unit can be running out from different parts of the map.
6) sometimes I've worked hard to capture ships and none of them end up being captured - each surrendered will be counted as lost.