Seems you hit the same wall than me a few weeks ago. I already had one AsyncTask
running perfectly, I copied the same structure for another one, tried to start it - no result. I was going already mad with it, when I reached this.
Resuming, all you have to do is:
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.HONEYCOMB_MR1)
new Task().execute();
else
new Task().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);