beginning with the flasher episode? When the episode ends you hear a jazzy instrumental version of the theme song with a still image of the last scene. Then, they go to the credits with the "la la la" closing theme.

Also, they just show the credits without them rolling up.

Yep. 3rd season will have another theme playing at the end, just before the closing credits, and will also have one at the beginning of the episode (after the opening theme)