Hi Moony
I'm one of those people you mentioned with the same problem. My theory is that the TV I'm using (it's a fairly old 51cm Teac), although it has component inputs, it doesn't fully support them.
I was lead to this conclusion because, when I have component video connected to my TV, the 480p (I think that's what it's called, I'm going from memory here) option in the TV settings of the Wii is available to be selected (it's greyed out if I don't have component plugged in). However, if I select this the picture goes screwy, like the v-hold of the TV has been incorrectly set. Or like the black screen that flickers at certain points in games like you mentioned, except at this point it doesn't flicker, it's constant!
I have learnt to live with it. It's an annoyance, but I do notice the improvement in the picture quality compared to composite video, so I put up with it.
I believe the only solution to get rid of the problem, is to get a new TV, or go back to composite video. I would like to be proven wrong though.
Good luck with finding another solution, and if you do, please report back here to help us all.
07/06/2008
Resident Evil 4
Brisbane, Queensland