Hi Marcos,
Let me answer your question, "Personal firewall is completely disabled" followed by a computer restart does NOT make a difference.
WiFi connection is still 'delayed'. There were no differences in my situation, no hardware changes only an upgrade from ess 6 to ess 7.0.302.26
Before the upgrade no problems at all. I have a Core I5 laptop with 6 GB ram, so this should not be the problem :-).
Maybe a tech can look into this because it seems to affect more users.