R12 Receivables - Credit memo is not crediting Tax line

Trying to Credit a entire amount on Invoice, Invoice is complete.

when we select credit allocation "lines and Tax"  and enter 100% percentage/Amount to credit , allocation happens fine .

but when be save the transaction only line amount is shown as credited, Tax amount is shown as balance due, it does not credit tax even after we complete the transaction .

Steps to create Credit memo .

1) Create credit memo - Transaction -> Credit Transaction

2) Select credit Allocation - Line and Tax , enter full amount to credit.

3) Save the transaction , only line amount is credited, tax amount is not credited.

4) Complete the transaction .