I had the same problem I then changed my router and it was fine...... If you have any old router lying about it might work.....There are other methods too.
Method 1: turn the backswitch of your ps3 and wait 30 minutes and turn it back again...
Method 2: Try to delete your playstation home save file by pressing triangle on the playstation home icon and pressing 'delete' (you won't lose any content but you will have to download playstation home again)
Method 3: Call Sony Entertainment and see if they can help you or you can e-mail them.
Hope this helps!!!