Don't know about Uncharted 2 but Heavy Rain runs fine from my external. There are not any +4GB files. I did notice that for it to do it's mandatory install the 1st time it boots, the game needs to be on the internal. Once it's finished installing you can move it to external and run it fine.
Originally Posted by nikita7
No select+x needed for Heavy Rain
Launch CECHA01 60GB now 500GB
Kmeaw 3.55 CFW
-The only disc a PS3 can rip is a PS3 Game Disc!
-New versions of multiMAN can be installed over old ones, no need to uninstall!
-If your games won't work, have you installed BDEMU2?