QUOTE(gamemaster9641 @ Apr 1 2010, 10:13 PM)

You can go to customize your network settings from XMB, and get to the part about DNS nameservers.
Select custom, and enter the following IP as your Primary DNS: 67.202.81.137
And there you go, PSN works.
So Basically All You Have To Do Is Make 67.202.81.137 your primary DNS and your ps3 will be able to connect to psn without any updates
( this is not my info just found it and reposted).
Copied from GeoHotz Blog, i don't know if i can though. If this worked for you, please reply with a yes, or a no. Thanks and happy hacking.
This works for me. Still on OS 3.15 and on PSN!
Console notified me update required when I turned it on and then I went and changed the DNS settings and now its all good.