Jar mismatch! Fix your dependencies

Don't Include the android-support-v4 in the library , instead you can add it to your project as an external jar using build path menu > add external jar

Sometimes you have to clean your project.

Use a Library Project just for the Support Library

As of ADT 22, using Eclipse Juno

I don't think any of the above are really the best answers. I also don't think it is recommended to use the external jar function in Eclipse anymore (AFAIK).

Rather, what worked for me is to create a separate empty library project.

Then use Android tools > Add Support Library to get the latest version you need or want.

Then remove the support lib jar from all other projects.

Finally, for every project that requires it, add a reference to your new Library project

(project properties) > Android > (Library box) > Add...

Then all your projects will have a single source to use and update the support library. This also makes javadocs easier to get working.

For info on how to setup the javadocs see:

How to attach javadoc or sources to jars in libs folder?

Remove android-support-v4.jar file from the libs folder from your project.