Android Assets with sub folders

"MyFolder/" + "MyFile.db3"

A filename for files added to the assets folder must be in lowercase letter. so,a filename such as MyFolder and Myfile.db3 is invalid. Rename them to "myfolder" and "myfile.db3",then everything will be fine.

Edit: was wrong about subfolders.
This code works just fine on 1.5 (for a file sample.txt placed under sub folder in assets):

InputStream is = getAssets().open("sub/sample.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(is));
String line = null;
while ((line = br.readLine()) != null) {
    Log.e("wtf", line);
}
br.close();

Are you sure you've got the names right?