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've had this problem too.
I had a project that was using the Google APIs (Level 7) as the build target. I'm guessing there's something awry in this build that doesnt point nicely to the appropriate theme files. To get around this, I switched my "Project Build Target" to Android 2.1-update1 and it seems to be ok.
To get there.. Within your project open, click Project (from the top menu) -> Properties -> select Android and change the build target.
I may find myself needing the GoogleAPIs at some point, so may need to change back. This may solve the problem, who knows.