That's been happening to me since I started playing v4, and reported it. Just assign fiefs at the hall right after you capture them to avoid any confused relation hits.
Could you please put this into our bug thread? That'll allow us to help answer easier and for people that search for bug fixes to find a quicker answer.
Actually. I thought it was just your characther becoming pscytsophrenic or really bad translation (Hrmm, who should I give my fief to? from Lord Dain, etc etc)
It happens to me every time though. But I'm playing the first full release not the latest.
I only lose relation when I take away a castle from one of your fisrt knights... I forget what his name is... that has been hapening to me ever since the beta.
hmmm... i thought i read somewhere that a patch would be made or was made that your relation would improve to 0 or such after everyday? so if you did something bad to your lords it wouldn't really matter :/ xD