Stop SAGE posting multiple transactions under one URN when system crashes

We have a problem where if someone is posting a receipt and SAGE then crashes, multiple receipts are posted under one URN. The net effect of this is the Sales Ledger is out due to the multiple posting however only one transaction is posted to the Nominal. If you correct the Sales ledger the nominal then becomes distorted needing a journal to correct the initial problem, if this was a one off I would not write this on here however this is happening on a monthly basis and our SAGE business partners say there is nothing we can do.