I'm confused. to use netflix on the player you have to hit the main menu button to get to the icons (device, network, settings). You choose the SmarTv icon to get to the page that shows the apps, and that's where you select netflix, from among Pandora, and like a dozen other little apps. Maybe you're skipping over some steps in your description, but i just wanted to make sure you're not launching the netflix app on your tv. On my LG tv I click one button and see the netflix app listed, like you described. on the 5500 it takes a bit longer to get to the netflix app.
Once i hit the main menu button and get to the main 5500 player menu, with the 4 or 5 icons you scroll through left and right (settings, network, devices) I've never had a disc start by itself once I choose to go to that menu. And I've never had a disc back me out of the SmartTv apps.