While it's not working for everyone, this PSN login fix appears to be working for most people. Lots of forum posters on NeoGAF are reporting the ability to log into the PlayStation Network with this fix, as the thread begins:
Go into your Network settings, and change your MTU setting to 1473, leave everything else however you had it.
Members from several regions are saying that this change is working for them.
[Via NeoGAF]
