Siege defence bug

Now this is something quite weird...

I finally got round to purchasing BI (had a gaming break for the last couple of months) and then, amidst my first campaign, I experienced something strange:
I was defending Londinium against the Romano-British with the Saxons, and they had built a considerable amount of siege equipment when they assaulted. they had, among other things, two towers of which one approached the walls under heavy fire from my two archers. now, they keep firing at the tower, my own wall towers help....and what happens? the siege tower deployed on another wall section begins to burn and then collapses without having taken more than, say, five salvos from a wall tower. Of course I continued shooting at the remaining tower....with the effect that one of the rams started to burn and was destroyed without having really being shot at. what the heck?? has anyone had similar experiences? those damned legionnaires in the tower I meant to destroy managed to get on the wall and beat the shit out of my wall troops (didn't have axes or hearths with me).
another weird thing is that siege equipment generally is displayed as being 0% damaged until a certain critical point when damage suddenly jumps up to 60% and then keeps on augmenting quite fast if the shelling continues.....the shelling of another tower in this case!
any observations, anyone? has BI introduced some kind of "overall siege equipment hit points" which causes random devices to be destroyed once the number passes certain marks? it's no issue with the installation because I installed it again after the incident, replayed the battle and it was all the same.... pretty annoying, that! my system is largely bug-free and BI patched to v1.6, so...I'm clueless. :help:

I've not experienced that, sounds very odd.

However I believe it going from 0% to 60% so quickly happens to us all, and is not a bug but a feature, fairly logically explained. When the siege tower has fire arrows chucked at it they mostly bounce off, however when one sticks the fire transfers onto the tower, thus it quickly catching on fire. When something catches on fire it's not usually gradually, it spreads extremely quickly.

I didn't noticed similar odds after I upgraded to 1.6. I had no problems with my Sassanid campain..
But I noticed that defence tactic of the AI has changed a bit. When you have forces at 2 different gates while attacking, the AI keeps their initial forces at both gates over a longer time, even when you have finally broken one of the gates and hit the city center, while you did nothing at the other gate. Strange, in the past they run very quickly to the city center after you start to fight in the city.
Something more happend in one battle:
I used a Siege tower to engage at the walls, after I destroyed the two flanking towers. The Romans positionated a unit just below the wall and stand still, while my peasants run to the gate and opened it for my main forces.
Just aside of the gate Romans had a unit of palatina at the walls... My peasants hit the bridge over the gate, so I took over the gate. AFTER that happend this palatina started to move at my peasants. I pulled them quickly out of the wall, while great units entered the door into the city. So my peasants are gone, the Roman unit stopped to move and did nothing against me, while I proceed into the city center! Even more worse, that unit got killed over the time by arrows shot of the undefended citys gates tower, now owned by me!?:no:

Another strange thing happend while defending a fort:
That fort blocked the entrence into Italy out of Austria with one peasant, because I got surprised by a Huns Horde. They build a ram, while I send out a few of my Aleman units to free the fort. In the battle I rid this place and rout the very small Hun forces engaged it this siege. Because I had some causualitys, I send my remains back to get refittted at Milano, while I left behind a small corps of 1 Spearman, 1 Commitantes-mercenary and 1 Lombard archer. Enough to handle unprepared Huns I thought.
But the very next tick a big army of Huns moved at my forts gate and used a ram to attack me. But they did not had the time to build one. It happend at the same time they moved up to me. I assume they can use the ram of the killed army before, because the remains of the beaten forces during the previous round had been part of the new siege. This should not happens!
During this battle I managed to kill lots of enemys, but finally got overhelmed by pure masses, so the fort changed it's owner ~:mecry:
Now I have to handle the Huns in Italy soon in a worser situation than I should do.