I've found three real bugs. The issue people are having with Freelancer isn't really a bug, it's an opinion about content. Freelancer in Brytenwalda allows the player to still obtain loot at the end of a battle, as with native. The game engine recognizes you as a one-man party, and your lord's army is an ally. In native Warband (and Mount & Blade), your party (even if it is only one man) always gets to select loot items at the end of a battle. This is a Warband issue, not a bug.
The three real bugs:
1. When you are enlisted with a lord, your avatar sometimes appears in halls, and the game seems to treat this avatar as a claimant (you can ask the king about yourself as if you were a rival claimant). Someone above posted a fix to this problem, however. Can he tell us which file needs to be modified? Does this fix require the Warband mod system?
2. Sometimes during battles, some kind of red text appears indicating an error. However, the battle continues and the game doesn't crash.
3. I can confirm that there is a problem with banners, regardless of the graphics pack. Banners don't appear anywhere in the game except as wall decorations in your castle. On shields which are supposed to have your personal banner (or indeed the personal banner of any lord which sometimes appears on a lord's shield or on the shields of his elite units) there is instead an invisible region. When these shields are seen in menus available for sale, they appear invisible also, with the rim of the shield and handle visible but with the texture where the banner is supposed to appear invisible. Furthermore, the presence of this invisible shield apparently causes the game to shuffle the locations of your companions. Strange, that. Banners which can be carried on battlefields also have this problem. The banners with a wessex boar or other art work, but ones with your personal banner or a lord's personal banner appear invisible, as with shields. I don't have the graphics pack installed and this error appears.
This may or may not be a bug, but there is another possible bug: during naval battles, the sky often has an unearthly yellowish or greenish fog. That has always been a feature of naval combat, and it isn't really a problem. However, on returning to land after a naval battle, sometimes various scenes will continue to show this strange atmospheric phenomenon. For instance, when it's foggy in a village scene, you'll still see the odd yellowish fog. This usually disappears after a day or two, presumably as the weather changes back to sunny or cloudy conditions. Then, when it gets foggy again, it's back to normal fog.
That's all I can find so far. Nothing game-breaking, but I'd say the banner issue really needs to be fixed. It looks odd seeing these elite guys running around with metal rims where their shield should be.