So this is what I did:
[*]Unlocked the 4 columns at the great statue.
[*]Completed the first two puzzles (the one at the great statue and the one with the nose).
[*]At the 3rd column I put in the cheese wheel, but I hadn't engraved it yet, so I had to put it back in my inventory.
[*]If I remember correctly, I also manually retrieved the weather vane from the column at this point.
[*]I proceeded to the 4th column, but was unable to figure out how to make it work (naturally :)), so I gave up after a few tries.
[*]I went into town, figuring out what to do to the cheese wheel to make it work.
[*]When I went back to the 3rd column, it had sunk back into the ground! As had all the other columns! And I could not re-activate them by the great statue either!
[*]I had no choice but to load the auto-save - this time I engraved the cheese wheel right away, and could complete the puzzle.
I haven't tried to reproduce this, as I no longer have that auto-save available, but I hope my recollection of events should be enough. Awesome game, btw. :)