Google has confirmed the bug in the Map API
on this group thread
Thanks for your reports. This problem is now confirmed, and is tracked
in issue 2212 : http://code.google.com/p/gmaps-api-issues/issues/detail?id=2212
This problem affects only certain customers, and is due to the bad
format of the JSON street view callback. We will keep the above issue
updated as the investigation carries on.