It seems like you have error/s in one of the interface .xml files. ADT(Eclipse) does not report those errors. This is where ADT Android project is a bit different from a normal Java project. An android project requires a constantly updated persistent R.java file. Among other things, the R.java file has all the resources IDs provided in the interfaces and maintains interface's consistency.
Have a look at this post, may be a quick fix to your issue.