I just bought Shivering Isles from the PS3 network last night and was very disappointed when the game constantly locked up during the quest, with Ice Veins, to kill the Shambles in the Garden of Bone and Flesh. If this is annoying you, I did find a workaround through trial and error to finish the quest.

Symptom: Entire game and console freezes or locks up when in the Garden of Bone and Flesh, or randomly in other parts of the game, when a new area is loading, or when attempting to save a game.

Cause: A bug, nonetheless, but I noticed the bug is triggered when the Shambles are attacked with arrows from you, the player (not Ice Veins) and you paralyze them in a manner where they are not yet dead, but also fail to stand up on their own. When attacking with an arrow and causing them to be paralyzed, sometimes they will not get back up. If this happens, the bug has been triggered. Not only will the Shambles not get back up, but Ice Veins won't get up either if knocked unconscious.

UPDATE: A few more hours into the game, I noticed this freeze / lock up happens anytime you paralyze a Shambles, even outside the garden, with an arrow; possibly affects paralyzing by other weapon as well.

Cure: Don't attack with bow and arrow! Attack with an alternate weapon. Get an alternate weapon if you have nothing but bow and arrow (the knights who attacked the giant should have one on them, go back and grab it before attacking).  If you are not skilled with a blade, change the difficulty setting by hitting start->options->gameplay and drop the difficulty to the lowest level. These Shambles are tough, so you will want to kill them quickly if not skilled with the blade. After defeating them, Ice Veins will offer to make the bones.

It's too bad this bug and workaround was not documented anywhere reliably. I searched the net for solutions, and could find NONE! However, for the PS3 version, I can say that this appears to solve the problem. I was about to request a refund on my purchase, however, this blog posting is my public statement of dis-satisfaction with no resolution being offered by the Playstation network (where I bought it), or Bethesda.

Best of luck with this solution.