It's happened on occasion in the past but now it happens daily. I've recently bought Playstation All Stars and I get disconnected just about every other game. It's so annoying.
I have verizon fios, use to use wireless, still got disconnected, now switched to wired and I still get disconnected, even though my upload speed is like 1mb and I never actually get signed out of my PSN just booted out of games. As far as I know, it's not a Playstation All Stars thing because everyone i've asked does not have this many problems. My internet and phone wifi do fine, as does my parents.
I have the same problem as you. Dont know how to fix it.