Page 1 of Pan & Scan....?

Okay, I know watching dvd`s in pan & scan mode is sacrilege - I agree. But i have a weird question. I own a Bush DVD2009 ( an excellent buy, I might add), and I get different results when playing back different discs in pan & scan mode.
For example, I watch The Thomas Crown Affair R2 disc in p&s mode and the pictures fine : I get a bigger 16:9 image on my TV (panned & scanned) rather than the smaller 2:35:1 picture you get in normal mode. However, when I try The Matrix R2, or even Fight Club R1, all I seem to get is the original 2:35:1 image, no blow up. How come? Is this definitely down to the discs? And how do I tell ?
Cheers.

Pan & Scan is a feature of the DVD spec, but not all discs use it. In fact many simply don`t, as it costs more money to have someone sit down and work out what to show.

The reason why some discs have both pan`n`scan (true not panned by your player) and widescreen on the same one, is simply that the masters for these existed already and didn`t require more than encoding.