Deposit getting error-ed out while applying partial payment

Hi Gurus,

Could someone help me in identifying the issue.

I am trying to apply a payment to an Item for which some partial payment was already applied.

When ARUpdate runs, it fails with Unique Constraint error.

Tracing the issue leads me to below SQL:

SELECT 242923,

  D.BUSINESS_UNIT,

  D.CUST_ID,

  D.ITEM,

  D.ITEM_LINE,

  MIN((D.ITEM_SEQ_NUM * 1000) + D.DST_SEQ_NUM ),

  COUNT(*)

FROM PS_ITEM_DST D ,

  PS_ITEM_ACTIVITY A ,

  PS_PG_ITEM_TAO4 I

WHERE I.PROCESS_INSTANCE = 242923

AND (A.ENTRY_AMT        <> 0

OR (A.ENTRY_AMT          = 0

AND A.ENTRY_USE_ID       = 'XX-XX))

AND D.SYSTEM_DEFINED     = 'A'