I see you have changed something and it seems to be better than what it was.
I suggest using an accumulative points system... where 1 star rating = 1 point.
Example: something with 5 ratings has a point value of the sum total of those rating points... 5 + 5 + 5 + 4 + 4 = 23 points. Instead of calculating the average.
This would also fix to a degree things that were rated low either by accident or maliciously.
Thanks