I finally decided to upgrade to Unity 4. I downloaded and installed the latest version 4.1.2 f1.
The Vuforia package does not show up in the asset store.
Further, when I download and run vuforia-unity-android-ios-2-0-31.exe, it says preparing to install, then when the status bar reaches 100% it just exits.
I'm using win7 64bit.
Any ideas as to what could be going wrong?