Hi Mélodie,
RC1 will not run in virtualbox, on my Alienware laptop.  I keep getting a kernel panic message about needing a 64bit machine.  This laptop has an Intel I7 processor (64bit).  Additionally, I burnt a live CD and it boots to a blank screen.  By the way, the MD5 checksum is fine.   I'll give it a try on a couple of other 64 bit laptops, when it get a chance.
Jeff