I have deleted a bunch of music from iTunes on my Macbook Pro, but am not gaining any free space I am trying to clear off a lot of extra space on my hard drive. I started with about 90 gigs of music today when I had about 45 gigs of space left available. I just deleted almost 40 gigs worth of music from iTunes and emptied the trash. But it doesn't show any increase in available space. 

I have been using the df -H terminal command to look at disk usage. This is the result:

Filesystem                          Size   Used  Avail Capacity    iused    ifree %iused  Mounted on
/dev/disk0s2                        249G   195G    54G    79%   47650435 13189307   78%   /
devfs                               188k   188k     0B   100%        636        0  100%   /dev
map -hosts                            0B     0B     0B   100%          0        0  100%   /net
map auto_home                         0B     0B     0B   100%          0        0  100%   /home
localhost:/klncoWvMIai4qlXuHftSwz   249G   249G     0B   100%          0        0  100%   /Volumes/MobileBackups
/dev/disk1                          3.3G   3.3G     0B   100% 18446744073707931462  1621231 1712789607586623232%   /Volumes/GSP1RMCPRXFRER_EN_DVD


I have also verified my disk, repaired it, and repaired permissions. Nothing is changing though.
I fixed the problem by resetting the PRAM and the NVRAM.