What is this "wobble" on my TV?

[Slinkoff]

Hello

General question. I've just bought myself a Panasonic TX36PL32 36" TV and a Denon DHT500SD all-in-one system and I absolutely love them. I have the DVD connected via component only and RCA audio from the TV going to the DVD, unfortunately I can't think of a better way to connect the audio as there's no optical/digital out on the TV. I've also got a Freeview box connected to a TIVO in turn connected to the TV.

Anyway, that's my setup, this is my query:

When I'm watching a DVD, using Progressive Scan, I occasionally get a bit of wobble on the screen, like heat haze rising off tarmac or as if the middle of the screen had some water on it. It's only brief and intermittent but it's noticeable. I'm new to this AV stuff, is this some known problem? Is it my DVD player or my TV? Is there anything I can do about it?

Also, with regards to my audio connections, which is better, RCA audio out from the TV to Audio 1 input on my DVD or using a scart in addition to the component connections between my TV and DVD and carrying the audio that way?

Thanks for your help.
Slink