ODS activation failed due to lesser SID

Hi Experts,

Could you please explain why this error happens when we try to activate a ODS delta load.

The error is "Request REQU_488V5LRSS9GS2DG0S9S1PBVC0 (585.692 ) for DataSource

0CRM_SRV_PROCESS_I from source system PCR410ALE has the status green and

a lesser SID (and is therefore older) than the request that you

currently want to update into the DataStore object"

Please suggest the different ways to fix this issue..apprecaite immediate response..

Thanks

Krishna