Couple of weird VI things

[econ21]

I had a couple of strange things happen to me in a English campaign on early in the VI and wondered if anyone else has experienced the same?
First, a castle held by the French that I had been beseiging fell despite my having no troops in the province. I had occupied the province two turns before but after a warning from the Pope, I withdrew on the previous turn to avoid excommunication. The castle fell despite not having any of my men to besiege it and so I was excommunicated. Irritating, but not fatal.
Second, I seem to have "lost" an heir. Prince John (of Robin Hood fame) was about age 15 on my list of heirs and so I was quite relaxed about the fate of 40 something King Richard I. Next time I looked, John was not in the list of heirs (or on the map) and King Richard was too old to have any heirs before he hit 56. Game over.
Anyone else experienced anything similar? (Wonder if the heir thing was something to do with John being Richard's brother rather than son, so when he matured, he did not count anymore?).

[Brutal DLX]

Very disturbing thing, to say the least. As far as I noticed, the brother should be the legit heir until the firstborn son comes of age. And therefore, he normally should show up on the map once he turns 16. Did you get a message that he is ready to command?
Could it somehow be (wild guess), that the besieging army was lead by your king, you retreated, but Prince John came of age, was placed in the besieged province, his unit suffered casualties in that turn due to the siege, and Johnnie unfortunately was amongst them? The castle fell, and the princes' unit got deleted? (or maybe there are 5 or so royal guards inside the castle now and you overlooked them?
Anyhow, I'm not currently playing a SP campaign, but I haven't experienced these strange things in my previous ones.

[econ21]

Ah - I never thought the two things were connected, but they did happen about the same time. I have heard that heirs can get disappear if they mature when the province the king was last in is held by the enemy. It still sounds a little buggy because apparently the Flanders was mine (despite the French occupying the castle and my troops all having left). I'll see if any of my old saves throw any light on it. Thanks.

[hrvojej]

The castle fell because the French "decided" not to sally forth. It won't be automatically retaken if you retreat, they have to act upon it. If there were many defenders still in the castle, the besieging force is supposed to lose a lot of men, so it might be the case that you lost all 20 royals if your king was besieging it. Maybe that's why they didn't sally forth, because the prince was technically there at that turn? Unfortunatelly, the rank doesn't matter as far as the besieger's losses are concerned, I lost the general of the besiging army at least twice. However, I haven't seen this exact thing happen either, so I'm just guessing.