Hi there,
Im having the exact same problem.
Have had my PS3 since the sdummer and have never had any problem accessing the PSN - have played online and purchased loads of stuff from the store.
About 2 weeks ago or so I can no longer get into the PSN - I get the same connection timed out message.
Weird thing is I can use the web browser to go online and when I go into netweok setting I am fully connected with 100% signal strength.
Im on Sky Broadband, wirelessly with a netgear router - is it something to do with either sky or netgear?