JIRA Full backup to XML - ZIP 4GB limitation.

Currently we have been trying both on our test system and on our Production system to create a full XML backup of JIRA data and have come across an error which does not allow the backup to finish. It mainly stops and say unable to backup to filename.zip.
Having looked in the logs it looks like there is a 4GB limitations like you can see in the log:
2013-09-15 05:43:03,132 http-80-36 ERROR karl.wilson 331x4900012x1 x4eb8a 127.0.0.1 /secure/admin/XmlBackup.jspa [jira.bc.dataimport.DefaultExportService] Error during XML backup.
org.apache.commons.compress.archivers.zip.Zip64RequiredException: entities.xml's size exceeds the limit of 4GByte.

Could you please help to find a workaround as we may need to move our data from MS-SQL to Oracle.
Thanks,

Karl