What wrong with Spamassassin? I have now seen this error several times when trying to migrate (older) VM's that have Spamassasin running so this is not an isolated problem.
I would suggest that's either a locked file that rsync cannot access - journal file so that would make sense OR its changed since rsync evaluated it for copying. Reckon you could try shutting down your MTA or content filter or spamd if thats what you're using then rsync - that way you're minimising locked files. HTH
