Metal Gear Solid 1080p Question

Here is the story.
When MGS4 EU version released i've rent it played for about 4 hours and it was displayed at 720p as the booklet says.
2 days ago i bought the Platinum version for 30 euros, the booklet says 720p.
My old save works and the old installation too, but the game is up 1080p now.
Any idea why?
Thanks in advance

 

my AU version has always been 1080p and that was from launch

 

I have AU version and it runs at 720p. From what I know that is the game's native resolution.

 

That is weird and i see no answers coming.

 

try checking the main resolution under display setttings on the xmb, but i got cod 4 and 5, on both boxes say 1080p, my main display is 1080p, even tho my tv is only 720p tv but w/e, cod4 displays only at 720P no matter wat tv for some reason, and cod5 displays at the same resolution set in the xmb. it may be a wierd thing with some tvs not sure, idk how the f**ck a 26" 720p tv can even accept 1080p signals.

 

IIRC its native res is 720P and it upscales to 1080P