为什么会发生这种R故障（Eclipse Android Java）？

Question

This is a continuation off of Why is my layout unable to be resolved? (Android/Java) (read the comments on the 1st answer) because I need to post a large amount of code, and doing that in a comment doesn't work.

package scouting.form;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;

public class Scouting extends Activity {

    CheckBox sground,strough,shigh,dground,dtrough,dhigh;
    Button logout,clr;
    EditText TeamNum;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_scouting);
        TeamNum=(EditText) findViewById(R.id.TBTeamNum);
        sground=(CheckBox) findViewById(R.id.CBSGround);
        dground=(CheckBox) findViewById(R.id.CBDGround);
        strough=(CheckBox) findViewById(R.id.CBSTrough);
        dtrough=(CheckBox) findViewById(R.id.CBDTrough);
        shigh=(CheckBox) findViewById(R.id.CBSHigh);
        dhigh=(CheckBox) findViewById(R.id.CBDHigh);
        logout=(Button) findViewById(R.id.Logout);
        logout.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                finish();
            }
        });
        clr=(Button) findViewById(R.id.CLREntries);
        clr.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                sground.setActivated(false);
                strough.setActivated(false);
                shigh.setActivated(false);
                dground.setActivated(false);
                dtrough.setActivated(false);
                dhigh.setActivated(false);
            }
        });
    }
    @Override public void onBackPressed(){}
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_scouting, menu);
        return true;
    }
}

Every line with "R.xxx.xxx" says "R cannot be resolved as a variable".

I tried doing a clean, and since it's almost definitely a glitch in eclipse, I tried importing android.R, saving and cleaning, then un-importing android.R(importing android.R breaks everything dealing with it, but I did that intentionally), saving, and cleaning, to hopefully "refresh" it to make the glitch go away. I also tried restarting Eclipse. Still having this bug.

Answer 1

I fixed it! So I had this file with the name "Gangam Style.mp3" in the raw folder(I have no clue how it got there). I noticed an error saying that was an invalid name. I went into the folder and removed that file, and all of the errors went away. I guess having a bad file kind of messed with Eclipse and for whatever reason, it couldn't find R.

To anyone else who gets the error that R can't be resolved, make sure you aren't importing "android.R" and make sure you don't have any file with an invalid name in any of your folders.