I had a bug were when I left the church ruins in Guilded Vale, with 3 weapons equipt on Kana, his fine Estoc (which was in his 2nd slot and not the bonus slot) would just dissapear every time, and only way I could get out and keep it was to only have 2 weapons in his weapon slots, which is how it's staying now since I dont want to worry about loosing any weapons every time I load an area.

 

It was a quicksave and I've saved over it stupidly but it happened every time I reloaded and tried it again.

Yeah, I encountered this bug too. I'm going to send my save file to the developers soon so that they can take a look. It's a very annoying bug, I'm not sure how many weapons I've ended up losing because of it.

Have you updated your game, DarthPizza? Kana losing his 3rd weapon slot was the result of an old bug that removed passive abilities when you equipped an item by double-clicking. It was fixed in the first patch, though.

So I don't see this keep happening, but it looks like I DID once lose a weapon when I removed kana and re-added him, the weapon from his SECOND slot disappeared.

Same problem In play in GoG version in Spanish, Windows 7. In 2 times (diferents games), I lost the weapon in in 2º slot in Kana.