wrong number range: How to use the unused order numbers?

Hi,

I have created an internal order type and assigned the internal number range 4210000-4219999. When I checked the numbers given for the system there are missing numbers. For example; the numbering is fine up to 4210004 numbered order and the next order has 4210020 number.

I checked the COAS table and there are no number used by any other order. How to use the skipped numbers? Is there any record of these unused numbers in any table? What can be the reason for this situation? How can we fix the problem? Is there any one who face the same problem?

Can anyone please provide suggesitions...

Thanks in advance!!

Regards,

Nidhi