I had some trouble login in Facebook with the skd 3.4. Finally the problem was that the hash generated by the keytool was different from the hash that the app was using. If you write this snipped of code in the onCreate method of your main activity you'll get the correct hash and then you can write it down in your facebook app control panel

GetHash.java

    try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    getPackageName(),
                    PackageManager.GET_SIGNATURES);
            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                Log.d("TAG", "Hash to copy ==> " + Base64.encodeToString(md.digest(), Base64.DEFAULT));
            }
        } catch (PackageManager.NameNotFoundException e) {

        }
        catch (NoSuchAlgorithmException e) {

        }