Follow thid guide to troubleshoot. http://www.tp-link.com/en/article/?faqid=637

Did you login its web interface to troubleshoot? http://www.tp-link.com/en/article/?faqid=636 http://www.tp-link.com/en/article/?faqid=637

No port forwarding feature on M5360 as you know. but can i do port forwarding for M5360? What does it mean? What are you trying to do? Why?

Did you try to remove network profile and reconnect instead of disabling and re-enabling wireless? Try channel 1 or 6 and channel width 20MHz.

Why upgrade? Any problems with it? I didn't any difference between 140305 and 140304... There is no error message during upgrade, right?

1) Antenna beamwidth (3dB, 5dB,... etc), Read specification for each product on TP-LINK website. 2) Chipset brand (Broadcom, Ralink... etc) and model, First and fourth one are discontinued. Second...