Post Script: Tried a siege the other day and the PC didn't reboot this time.

I think it was a keep-level castle but its came with a wooden palisade attahed to it. Luckily, there was only one unit defending (MtdSgs) and they were in the outer enclosure, so I didn't have to tackle any inner gates. I had one catapult with me, which I deployed to one side, so it could hit both the stone wall and the stockade, if need be. Whilst it went to work, I thought I'd give these flaming arrows a try.

One unit of Bulgarian Brigands, one wooden wall, only three casualties and probably less than five minutes later, there was a nice second hole with which to send a second unit of cav. I swear they made quicker work of it than the catapult. Took a nice screenie of the smoke trails in mid-flight but probably won't post it here as I guess you've all seen this already.

I have to say that they've used considerable license in terms of the time needed to knock down/burn castle walls but the conventional battles, which ought to take hours, are over in mere minutes (Shogun style) so 'time compression' is something we've got used to anyway.