Hi,
The mech is out of alignment.
As far as i know...there was no start up bug on this model.
I have been on a Sony service traing course for this model...and nothing was mentioned about this.
Sorry but you will need to take it to a suitable repair shop.
I have repaired many of these units with this fault.
It just needs the mech re-aligning.
I hope this has been some help.
Gordon
April 2010