So, I used ODIN to flash CWM and got to the recovery menu. The first thing I notice is that it can't access certain stuff (system partition, for one), but I still kept going. The only thing I tried was to do a backup with CWM, and it start as it does a boot and recovery .img backup, but once it tries to do a system backup it gets to the same problem about not being able to mount it. Is this normal or am I doing something bad? Because of this, I stopped my effort of installing a new ROM because, if I don't have a safe and full backup of my Stock ROM, I don't want to risk it using another one.