Ever since I started using remote play on my PSP I haven't touched the PS3 for
about a good 2-3 days. I have the PS3 set on Remote Start to "On" so I can
turn the PS3 on and off when I am away. Now today I get on to play online then
all of the sudden I am often lagging (red bar signal) and so on. Whenever I am
the host of the game, after I've been playing for 2 to 3 minutes, it automatically
ends the game without my consent. Anyone having similar issues? Is there a fix?

Do you get dropped back to the main menu?

I don't have these issues but I recall a few times where the game stopped and it took me back to the menu (one with play online). What games are you trying? I know that some of the larger games (ground war) require more bandwith to host. Now with the EU patch I get more laggy games but that is out of my control since the game does not let me filter bad connections.