At the toll house, once you engage in a dialog with Anders and you "end" the dialog, the game doesn't let you save. You get a warning saying you can't save in mid-dialog ...
Even after fighter Anders and his crew, and after going to camp for a rest, you can't save - for same reason. Reloading the previous save, before meeting Anders, will not help you. I had to reload the game with the "previous" save that I couldn't save before and then it saved.
I was not able to reproduce the bug
Ok, I think I figured out how to reproduce this bug - I'm not in front of my computer to confirm this, so if someone can confirm this pattern, let me know.
So first, it has nothing to do with Anders dialog.
It's when you shove someone, like the mage at the toll house - you shove her out of the balcony - a dialog will pop and if you DON'T interact with the dialog, when she hit the ground and die, the dialog will close by itself.
-> I believe it's at that moment that the system/game will prevent you to save, no matter what you do. It's like the "dialog" is still open, but you can't see it.
-> Also, Anders crew won't be hostile right away, up until you are in sight with Anders/crew.
If it's the case, your saves (previous one) will get bugged if you reload old save. you will have to quit the game and re-initiate.
There are other places when you can shove someone, that I believe the same behaviour might happened, ex.: the goblin at the first camp on top of the rock, or perhaps the Minotaur in underdark.
if someone can confirm that, it will be great.