Manual reconciliation of BP

Hi ,

I have encountered one issue in manual internal BP reconciliation.

One of my users complained that one invoice is reconciliated twice with one payment and now the invoice status is showing as applied amount is double of the invoice amount and balance due is showing in negative of the invoice amount .

I am wondering how it is possible, when we do manual reconciliation it immediately refreshes the screen and the invoice and payment disappears.

Any idea how I can track it.

Rgds

Suman