I have been having what looks like a similar problem, where eventually, whatever it is I’m watching, we come across a spurious ‘weak signal’ message. The host machine is still on Win7 x64 (for now) and dynamic tcp port range for ipv4 was set to start at 1025 and number of ports to 13976 ports, strangely enough. FWIW, UDP and IPv6 ranges were nominal. I’ve since changed it to the defaults you’ve mentioned. Not sure if this has made a difference yet, but just thought I’d mention it.
(Oh, and I don’t know if there is any equivalent to the KB you mentioned above for Windows 7, or if they’ve made changes there recently to the stack at all.)
