The location shifting when reloading a save in the Xbox version is a known issue. Try reloading an earlier save (like the last auto-save) and then your most recent save. If that doesn't help, back out to the dashboard, and then load it again.
Control suggestions & bugs (Xbox 360)I don't have the game yet, so don't know what level (or tactic) would be good for the troll. You should be able to wander around a bit and find other things to do or places to explore first, though.
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