无法解析属性“src”中的drawable

I'm having a problem when trying to load various images to an image button using an xml file in the drawable-mdpi folder. It worked for one button but doesn't work for the other. The code works for the second image button but not the first, I get the error, " main.xml: Unable to resolve drawable "C:...workspace\AndroidAlarm\res\drawable-mdpi\keyEntry.xml" in attribute "src". I did the exact same thing in the first imageButton that I did for the second. The xml file for the second button (working one) looks like:I'm having a problem when trying to load variou