Yup, the new demo for Uncharted Drake's Fortune seems to run only on U.S console regarding new post on Neogaf forums. PS3 are freezing with a black screen or they ask you to insert a disc.
Maybe it's just a bug, who knows ?
Here there is one post illustrating the problem
"The people complaining about the two problems (blank screen, insert game disc), do you have a PAL system? I'm wondering if somehow there's something messed up there."