Distinct Shows Dupes Instead of Distinct

Select DISTINCT [ADJ COUNT]
From [dbo].[SPBMI_Count]
Where [Index Key] in ('SPGBBMBMI-USDFF--P-REMS--', 'SPGBBMBMI-USDFF--P-RGUS--', 'SPGBBMBMI-USDFF--P-REMX--', 'SPGBBMBMI-USDFF--P-RGUX--')

I keep getting 8 records returned, but there should be only 4, as all Index Keys are unique.

I tried to figure this our using the execution Plan, but that doesn't help.  I also tried to figure out what SQL Server is doing by debugging, but it just runs through the logic in one step.  How can I see what's really going on behind the scenes.

Thanks experts!!

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