Panasonic SD H80 Lens cover

Hi i recently purchased a panasonic SD H80, it worked brilliantly for a week however on turning it on one evening the message "condition too dark, or open lens cover" came up, this is despite the fact the lens cover is OPENED, i cannot understand why it is doing this, and my LCD screen remains black, it will record and u can hear sound but NO picture format, can u help????
Many thanks!