Mysterious failure to call methods

JTox.c

JNIEXPORT void JNICALL Java_im_tox_jtoxcore_JTox_tox_1onfriendrequest(
		JNIEnv * env, jobject obj, jlong messenger, jobject callback) {
	tox_jni_globals_t *_messenger = (tox_jni_globals_t *) messenger;
	if (_messenger->frqc) {
		if (_messenger->frqc->jobj) {
			(*env)->DeleteGlobalRef(env, _messenger->frqc->jobj);
		}
		free(_messenger->frqc);
	}

	friendrequest_callback_t *data = malloc(sizeof(friendrequest_callback_t));
	data->env = env;
	data->jobj = (*env)->NewGlobalRef(env, callback);
	(*env)->DeleteLocalRef(env, callback);
	_messenger->frqc = data;
	tox_callback_friendrequest(_messenger->tox, (void *) callback_friendrequest,
			data);
}

static void callback_friendrequest(uint8_t *pubkey, uint8_t *message,
		uint16_t length, void *ptr) {
	friendrequest_callback_t *data = ptr;
	jclass class = (*data->env)->GetObjectClass(data->env, data->jobj);
	jmethodID meth = (*data->env)->GetMethodID(data->env, class, "execute",
			"(Ljava/lang/String;[B)V");

	char buf[ADDR_SIZE_HEX] = { 0 };
	addr_to_hex(pubkey, buf);
	jstring _pubkey = (*data->env)->NewStringUTF(data->env, buf);
	jbyteArray _message = (*data->env)->NewByteArray(data->env, length);
	(*data->env)->SetByteArrayRegion(data->env, _message, 0, length, message);

	printf("definitely happening");
	fflush(stdout);
	(*data->env)->CallVoidMethod(data->env, data->jobj, meth, _pubkey,
			_message);
}

JTox.java

	/**
	 * Native call to tox_callback_friendrequest
	 * 
	 * @param messengerPointer
	 *            pointer to the internal messenger struct
	 * @param callback
	 *            the callback to set for receiving friend requests
	 */
	private native void tox_onfriendrequest(long messengerPointer,
			OnFriendRequestCallback callback);

	/**
	 * Method used to set a callback method for receiving friend requests. Any
	 * time a friend request is received on this Tox instance, the
	 * {@link OnFriendRequestCallback#execute(String, String)} method will be
	 * executed.
	 * 
	 * @param callback
	 *            the callback to set for receiving friend requests
	 * @throws ToxException
	 *             if the instance has been killed
	 */
	public void setOnFriendRequestCallback(OnFriendRequestCallback callback)
			throws ToxException {
		lock.lock();
		try {
			checkPointer();

			tox_onfriendrequest(this.messengerPointer, callback);
		} finally {
			lock.unlock();
		}
	}

JToxTest.java

package im.tox.jtoxcore.test;

import im.tox.jtoxcore.JTox;
import im.tox.jtoxcore.ToxException;
import im.tox.jtoxcore.ToxWorker;

import java.net.UnknownHostException;

public class JToxTest {
	public static void main(String[] args) throws UnknownHostException {
		try {
			JTox jtox = new JTox();
			jtox.bootstrap("66.175.223.88", 33445,
					"AC4112C975240CAD260BB2FCD134266521FAAF0A5D159C5FD3201196191E4F5D");
			System.out.println(jtox.getAddress());
			jtox.setOnActionCallback(new TestOnActionCallback(jtox));
			jtox.setOnConnectionStatusCallback(new TestOnConnectionStatusCallback(
					jtox));
			jtox.setOnFriendRequestCallback(new TestOnFriendRequestCallback(
					jtox));
			jtox.setOnMessageCallback(new TestOnMessageCallback(jtox));
			jtox.setOnNameChangeCallback(new TestOnNameChangeCallback(jtox));
			jtox.setOnReadReceiptCallback(new TestOnReadReceiptCallback(jtox));
			jtox.setOnStatusMessageCallback(new TestOnStatusMessageCallback(
					jtox));
			jtox.setOnUserStatusCallback(new TestOnUserStatusCallback(jtox));
			Thread worker = new Thread(new ToxWorker(jtox));
			worker.start();
		} catch (ToxException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

Output

3A9236B1D04B0BC45330E8E3FC3CBB5D640531D7196FCF2424D163F3FCC3E57CEC0A431D590D
definitely happening

TestOnFriendRequestCallback.java

package im.tox.jtoxcore.test;

import im.tox.jtoxcore.JTox;
import im.tox.jtoxcore.ToxException;
import im.tox.jtoxcore.callbacks.OnFriendRequestCallback;

public class TestOnFriendRequestCallback extends OnFriendRequestCallback {

	public TestOnFriendRequestCallback(JTox jtox) {
		super(jtox);
	}

	@Override
	public void execute(String publicKey, byte[] message) {
		String msg;
		if (message == null) {
			msg = "No mesage";
		} else {
			try {
				msg = JTox.getByteString(message);
			} catch (ToxException e) {
				msg = "ERROR: Unable to get message";
			}
		}
		System.out.println("We received a friend request from " + publicKey
				+ " with the following message: " + msg);

		try {
			jtox.confirmRequest(publicKey);
			System.out.println("confirmed!");
		} catch (ToxException e) {
			System.out.println("Unable to confirm friend request");
		}
	}
}