Thanks Brian.  I thoguht that maybe I could open a back door by doing something like that yesterday, but I ran into some problems.  The site won't register a new user. (That's what got me started on trying to 'fix' things)   I can't edit the database remotely.  Looks like I'd have to 'buy' a database export from the hosting company and set up dnn on my home desktop and try to use the exported database.  Sounds all logical, but not having done that I'm not sure I could make it work, especially with a dodgy db to begin with.   Good idea about the keys..I'll go back to the web.configs and comapre them.  That might give me a clue as to what's going on , I hope.   I'm beginning to think it might be easier to wipe the whole site clean and start from scratch again.  At least there's some things I know what NOT to do ;-)

cheers