Quote Originally Posted by phred
Playing as the Franks, I was attacked by the Saxons. Over the next two turns I raced my army to their only city to beseige it, only to find that we were now neutral.
I declared war and beseiged the city anyway, and the next turn the seige was broken and the Saxons and Franks were neutral again.
I finally loaded the Saxon city with spies and beseiged the city until my spies opened the gates. I had to beseige it a couple of more times and every time I hit end turn, I heard "the seige is broken" and the Franks and Saxons were neutral again.

Not once was I approached by a Saxon diplomat and given the option of making peace - the game just automatically reset the Franks and Saxons to neutral.
That can be explained by the Saxon allying with an ally of yours each and every turn. You enemy allies with your ally means a return to peace. Look it up.

Gustav, the last one I have reported earlier, it is not a bug per se, but a failure to grant a family member a unit of bodyguards. player1 has posted a fix in another thread (So... I think).