I have recently installed Eclipse IDE for Java Developers (Version: 3.6.1) with the Android SDK Platform 2.1update1 - on Windows 7.
I can add, edit and run code for
I had this same problem.. I am using Android 3.0 and developing for the Xoom, and it was already selected. However, changing the version to 2.3.3, and then back to 3.0 also solved the problem.. No rebuilds, re-import of the project, just changed the version, and changed it back again to it's original value. But that may be specific to 3.0. Once solved I didn't go any further into it..