The guide is full screen on the 350 tv out, before that the guide displayed a small live tv on the top right corner, i liked that way.

how can i make the guide appear like before the pvr 350 tv out change ?

If you are not watching tv already and you go into Schedule Recordings, then the guide shows up full screen all by itself.

For the other way, choose Watch TV, then hit... I think it's the Guide or the Go button (one of the upper left buttons on the silver remote). That'll bring up a menu. Choose Program Guide and it'll display the listings while continuing to play the current channel in a small window in the corner.