It is some times a disadvantage, while you do not want this feature. By default it is recovering faulted instance form 00:00 hours. If your instances are still failing, that soa-infra tablespaces grows.
The feature can be disables or changed on an other time, via Enterprise Manager by setting the BPEL property under soa-infra -> SOA Administartion -> BPEL Properties -> More Advanced BPEL Properties -> recoveryConfig.
Put the value maxMessageRaiseSize to 0, to disable auto recovery. I even set the begin and end time the same.