Exchange Backup to Folder Incremental Job fails - Timestamp error

Hi

I have created a backup to folder job that does a full backup of Exchange every Friday but in the week I also do incremental backups to folder.  The full backup works ok but for the incremental jobs I receive the following error:

 

<description>Backup set #1 on storage media #1 Backup set description: "incremental backup"</description>

 <backup_type>Backup Method: Incremental - Logs (flush committed logs)</backup_type>

 <agent_started>Microsoft Exchange Server Agent: Started</agent_started>

 <granular_restore_enabled>The option to enable the restore of individual items from the database backup was selected for this backup.</granular_restore_enabled>

 <start_time>Backup started on 26/10/2010 at 23:00:41.</start_time>

 <media_label>Media Label: IMG000021</media_label>

 <pdi_location>GRT backup set folder: D:\Exchange Inc\IMG000021</pdi_location>

-<database>

 <database>Database Logs ( E040000A52F.log - E040000A535.log )</database>

 </database>

-<OperationErrors Type="extended_err_abort_oper">

 <UMI>V-79-57344-759</UMI>

 - Unable to complete the operation for the selected resource using the specified options. The following error was returned when opening the Exchange Database file: '-515 The timestamp in the next log does not match the expected timestamp. '

 </OperationErrors>

 <end_time>Backup completed on 26/10/2010 at 23:00:56.</end_time>

-<summary>

 <backed_up_exchange_store>Backed up 0 Exchange Server stores</backed_up_exchange_store>

 <new_processed_bytes>Processed 11,695,830 bytes in 15 seconds.</new_processed_bytes>

 <vlm_hist_rateformat2>Throughput rate: 44.6 MB/min</vlm_hist_rateformat2>

 <compression_type_used>Compression Type: Software</compression_type_used>

 <compression_ratio>Software compression ratio: 2.8:1</compression_ratio>

 </summary>

 <empty_set_warning>This backup set may not contain any data.</empty_set_warning>

 <filler>----------------------------------------------------------------------</filler>

 </set>

 </machine>

 

Can any one help or point me in the right direction?

 

Thanks

Matt