Adjusting audio to video delay for Plasma screen ?

[Aquarius]

Hi,

Can someone explain to me the scrub issue when using Movie sync offset in proTools ?
Some guy at Digi told me that if i use a Canopus box, it will be a set and forget operation (22 quarter frames for Pal)... I don't understand it now after reading the posts on the plasma thing ...
We 're trying to sort this thing at the moment and sometimes I feel aaaaaargh !!!!
Also, how do you calculate the proper delay in the audio path ?
Might be a stupide question but...are you estimating it by watching the lips untill it feel confortable ?
I do use a Tascam DSM 7.1 so the internal delay could be a solution for me.

Peace,

Olivier