might just be a random glitch in your computer..... my laptop had similar problems with utorrent but my old desktop, which has the same antivirus installed and is using the same router still works fine........ when my laptop rejected utorrent i just downloaded vuze (formerly azeurus) and it worked brilliantly...... maybe you should try that if you can't find a solution..... (vuze is a java application so make sure you have that installed if you don't already if it comes to that option)