Comment 7 for bug 287158

I checked 1.4.7 with valgrind (calgrind was just a typo in previous post) and there is no trace of race condition in disconnect any more.

Solution to this might be either to push 1.4.7 to intrepid or backport network_worker.cpp. I don't know which one is preferred but both should fix the crash problem (that has about 25 % chance to happen in my system while disconnecting)