The first thread can be found http://www.gamesas.com/topic/1408842-hearthfire-bugs-report-part-1/
The Heljarchen grain mill refuses to work, no interaction option at all with the thing.
No idea how I caused this bug, and the usual, reloading, waiting for the house to reset or attempting to blow it away with a shout have failed. Climbed all over it, swore at it, attacked it. Nothing.
I am reasonably sure it worked when it was first built, but will have to check and see how many wheat sacks that character has to be sure she ever used it. It is the second playthough for this character so it might not have been on this one she was using it.
The family are currently living at the house, I will try moving them and see if that helps.
Edit
Moved the family and dog, nothing changed.
She has 30 bags of flour in storage and has done some cooking with the oven, so it did work when first built.