Log Warning "The initial full backup version is not accessible at the moment"

Since build 6131, I get this message on every backup, which marks the backup with the Triangle warning sign, so that all backups on the log look suspect, yet they appear to complete perfectly.
This message appears between - "Priority changed to high" and "Updating backup database: setting verification requirement for data base access"
Later in the log, I get the backup created message and the validation successful message.
I get the same warning on 2 x XP systems and 1 x W7 system for my 3 licences.

What is this warning message telling me? and if it is not vital, can it be removed by Acronis? as it appears to be incorrectly showing every backup to contain some sort of error, when on the face of it, they are all Ok.