There are about 20 of these cases. I know I could combine the unique values manually by grouping, but I have 100 of these layers to process, so I would like to correct the problem so they don't happen in the first place. The fact that so many duplicates and triplicates exist makes me wonder what's going on behind the scenes and if there's something strange with my data or the way the raster is formatted.
It appears that you are trying to display a continuous variable using discrete values. You may want to either display the features as a scaled gradient according to the magnitude of your value column, or possibly just reduce the number of classes in your classification to match the number of unique values that you have in your dataset.
If the field is numeric, try clicking the remove all fields button, then clicking the add all fields button to see if the fields will be consolidated.