Where's my ransom?

Last night, playing my English campaign, I got the "kill my Dad" message from the heir to the Scottih crown. I'd left Scotland alone until this point and actually had good relations with them. I figured I could go kill the King, collect the money and enjoy a long lasting peace with the then increased relations afterwards. So off i went. I took a leet army up to Edinburgh and me the King's army in the field. I captured the King and another of hissons. When I ended the battle I got offered 18000+ for their release, which was odd since the only remaining family member was the son who wanted them dead :dizzy2:. Being the greedy ruler that i am, i took the money and released them - watching my coffers swell in the process. i was pleasantly surprised to then see that the mission to kill the King was still valid so, in the same turn - having ust released the King and his son into Edinburgh - I sacked Edinburgh. I executed the prisoners (hoping to collect my 5000 from the Heir) and sacked Edinburgh for nother 10000 ~D So far, so good. Except when I end turn, I never got the money for the mission cause Edinburgh was the only city and I wiped out the faction - fair enough. BUT... the money I got from the ransom - the 18000 florins - was also not there! it disappeared. So out of a potential 33000 florins i got 10000 which was from sacking Edinburgh. I was robbed! How can ransom money be taken back after it's been paid? So I'm now 20000 short and not at all happy. I'm goig to vent my frustration on the French.