Yes, I'm in a similar situation. I'm convinced I've been peanalised for duplicate content. I had a full page portal from a PPC search company, on the front page of a domain for over a year whilst I developed the site. I was stupid and linked that site into my network, so I could earn some money from the full page portal. I've now spent 6 months designing the site, and it seems to be penalised. I don't know whether to wait for google to realise the page has changed, or change domain name and host. The site has been spidered during the last week, yet still no change. The front page has been visited 6 times at least.
Also check if any results come up when you do a search for the domain name in google with the www and dotcom. For me results appear if you search for the domain without the www or dotcom, but not with.