Disney Universe is a 3.60+ game so it won't work on 3.55 CFW as of yet (like mentioned above).
Need for Speed Shift 2 Unleased should work on 3.55 CFW with mutliMAN and Select + X and an Eboot.bin fix.
Here it the Eboot.bin fix (below), make sure to replace the original Eboot.bin file with this one. You can also use EbootMOD/Fix (http://www.ps3news.com/forums/ps3-ha...#post372938)to fix 3.56 games.
3.55/3.41 Eboot fix by MOTE for the BLUS30580 version of game - http://uploadmirrors.com/download/1S...ix_by_MOTE.rar