Unable to find a manual credit memo due the system hanging

Hi,

The user wants to create a manual credit memo and its sequence is automatically.

When the user creates a manual credit memo the system hangs and the manual credit memo sequence number was 8 .

After he reopons the system again he did not find it then according to this he creates a new manual credit memo and we surprised that the new manual credit memo number was 9.

Why the system dismissed the number 8 from the sequence.

This issue on our Production and it is very important to get the lost manual credit memo because the sequence will not be orderly and it may this issue comes again, also we use this sequence in front our Tax authority, so when we lost the sequence it will be bad image in front of our Tax authority.