I am attempting to import a private key that was made in Multibit, into Armory. I am able to restore this key into other wallets, such as the Android Bitcoin Wallet, Mycelium and Electrum, but when I attempt to do so in Armory I get an error saying "The private key you have entered is actually not valid for the elliptic curve used by Bitcoin (secp256k1). Almost any 64-character hex is a valid private key except for those greater than fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141"

Is my key is the wrong format or something?