Oracle Database Express Edition (XE)

Hello everyone,

I just installed 11g XE on Oracle Linux 5.2 64 bit (inside VirtualBox running on Windows 7 64 bit). All seems to work well, I can access Apex, SQLPLUS, etc...
However, when I try to run the BACKUP DATABASE, I keep getting:

==================== ERROR =========================
Backup of the database failed
==================== ERROR =========================
flash recovery area is not enabled.

I have checked and rechecked my parameters and all seems fine to me:

SQL> show parameter DB_RECOVERY_FILE_DEST;

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /u01/app/oracle/fast_recovery_area
db_recovery_file_dest_size big integer 10G

I have even reset these parameters just in case but still no luck.

Would anyone know what could cause this?
Thanks!
Francois