crash/dupe bug

The game crashes for no apparent reason, generally when I am simply walking in normal overworld terrain (plains, etc.). When this happens, the game state is rolled back for some time between seconds and minutes – presumably to the last auto-save – and one or more items in my inventory have been duplicated. (sadly, they've been things like saddles, not diamonds!) I would estimate that a crash occurs every 5-10 minutes of play, on average. Needless to say, this is making the game unplayable, along with the dupe/loss bug I just reported.