I am using the latest version now but the really annoying thing I find in it is there is no way to import keys directly, it only shows the sweep function and I don't know if there is a way to do it in console. I don't understand the reason behind removing that feature, it was so useful for when one needs to import paper wallets instantly.
You will have to create a new wallet and when creating choose restore wallet to import private keys. If you have already created a wallet with seed, you can't import an address. It is mainly to prevent users' loosing their funds due to lack of backup. I started creating two wallets. One with seed and another for importing addresses. I suggest you do the same or use other wallets like Bither and Multibit.