Hello, I have been using Mintcoin qt on my Ubuntu machine for a few weeks. I am having a problem with the wallet opening, it shows the green loading screen with the Mintcoin logo on it, but it gets stuck "Loading block index"

I'm not very linux knowledged, so any help world be appreciated. I had a tough time just figuring out how to install the dang wallet.

Also I'm having difficulty finding the wallet.dat so I can backup. I know the wallet qt has a backup feature, but I need to know where the wallet.dat is stored in case I need to import my existing wallet.dat into a newly downloaded qt.

Thanks, hep is much appreciated!