I had a tech at a local camera shop tell me that I should use an EH-5 AC adaptor when cleaning my D70 CCD. Not for the usual reason - that a battery failure will cause the mirror to unlock while cleaning. Instead, he says that the CCD loses its charge while under AC power (when the mirror is locked up). Has anyone heard of this? I didn't really believe him, but tried it and it actually seemed to help a lot.