Originally posted by Python
1. Turn off your PS3, your router, your modem, etc.
2. Let everything stand turned for at least one minute.
3. Turn on you router/modem and wait for full power up (i.e. All lights lit)
4. Turn on your PS3 and try to access PSN
-IF PROBLEMS PERSIST
1. Go to Settings>Network Settings>Internet Connection Test
2. Post the results here.
Well, this has been working for me at the moment, thanks for the suggestion Python