Problem Playing Blu-ray: PS3 & Samsung

[chadz001]

I have a Samsung (4-series) TV, like this:

Samsung 40"

And it displays games fine (to a quality that looks of HD). However when it comes to playing blue-rays it generally doesn't display the image that clearly:

- when the actual film plays it's sort of 16:9 format, slightly grainy with big black bars top and bottom.

- it is playing at 1920x1080 (both my TV and PS3 confirm this and I can see a clear difference from the lower 720 setting)

- when watching a blue ray (I've tried a few) occasionally one scene in the film will appear crystal clear and unboudtably HD - note I say a SCENE - it doesn't flicker suddenly - it's at some not so aritrary interval.

- the splash screens that you get as the blue ray is loading tend to be very clear and fill the whole screen.

- it generally seems to upscale DVDs better than it plays Blue ray disks.

This confuses me because - I'd guess it's not a problem with my PS3 as it plays games fine - the blue ray player must be working otherwise it wouldn't display games clearly - right? Also I would not have guessed it to be the TV as it seems to display the odd scene in HD. A nice example is viewing text in the web browser - it is nice and clear.

- I'm using a HDMI cable.

- When I try and setup the output quality from the PS3, it gives me options fro 1080p and 1080i, if I select 1080i it works fine (and that's what I'm using), when I select 1080p, in the past I've seen it flicker as if half manaing to use that setting but generally it doesn't like it.

I get the feeling there is some setting somewhere that I'm missing?

Help please!