I am facing this same issue.

I set recvfrom to have a timeout of 5 seconds and stuck it in an infinite loop with some response code based on what is received.

The sending functionality of the socket is not compromised at all. It can always send. However, after about 10-20 minutes of normal operation (i.e. packets are being sent and received properly) - python stops being able to receive packets (but is still able to send them).

Cross-checking this with wireshark showed me that incoming packets are being received by the system (so the problem is somewhere between receiving them on the network adapter and accessing it in python).

I'm running 64bit Windows 7 with 2 network adapters (wired and wireless).

I also tried running the same python script in 4-200 processes simultaneously (but on different ports), and the error happens at the same time for ALL windows.

All firewalls are disabled.