Offizieller Kommentar
I asked them for an update recently and just heard back - they feel the issue is hardware related and you should send the unit for in-warranty repair. If you find that the local authorized shop doesn't do an adequate job, it can be sent back for repair on the same issue even if it is out of warranty. The alternative is to send it to Pioneer's service center in Long Beach, CA. You can find technical support contacts here.