I was having the same problem.... I figured it out lol
What did I do?
-Go on your PC
-Open Network & Sharing Center
-Click Adapter Settings
//Un-share Networks & Remove ANY Bridges
-Select LAN & Your WiFi
-Right Click & Add To Bridge
-Connect To PSN
-Disconnect From PSN
-Remove ONLY YOUR WIFI From The Network bridge
-Share Your WiFi With The Bridge
//It Should Give You The Option, On My Windows 8 PC It Makes Me Share With A Different Connection, BUT I Can't Share With LAN
( THAT'S WHY I CHOSE THE BRIDGE!!! ) For Some Reason... It Gives Me The Option On My Windows 7 PC But Doesn't make Me Share With A Certain Network
Go To PS3...
-Network Settings
-Internet Connection Settings
-Custom
-Wired Connection
-Now just keep pressing X until you're done
That is how I fixed my connection problem after having the same thing you have. If it doesn't work let me know, never thought I'd be helping you lol