I have the G Tablet and only had a 512mb mini card to start. It worked fine. I ordered two new Kingston 8G cards to get extra capacity but when I replace the 512 with either new one I get a message that says the card is damaged and I need to format it. I tell it to do that but nothing happens. Any ideas with what might be going on? Also, both cards work on my PC when they are in their adapters.