something still runs in background when I close my webView

I'm using unity webPlayer for create a tool witch interacts with maya (using TcpClient sockets). I'm loading the webPlayer in a PyQT MainWindow in maya (I'm loading the html file with QWebView.load( my url ) int this window which is parented to maya) .

My problem is that when I close the QWindow, it seems that unity is still running in background somewhere and so I just can't quit maya correctly (the maya process is still running after I click on close because a process still runs ) ... I've checked many things but it seems that it's the fact to load the unityPlayer Plugin wich is the cause of the trouble...

So I was wondering if the unity plugin could launch something which prevent the maya process from closing...