UMD region lock help

ok, I bought a USA psp and upgraded to 2.6 via a UK game (street fighter).

I had thought that now UK region (region 2) umd movies will work on my psp, but I bought KingKong (on the back it has a few world icons and a number in each, also has 2, presuming that is supports region 2) and it says region error, etc :S

Please some1 clear up that upgraded does not change the region? and also how to check the region of a Umd movie from the case.

thanks

Nope, but messing around with the flash sometimes changes it... [specifically DK folder]