hang on df -h command

[effemmeffe]

Hi, I'm using the latest XBian 1.0 Alpha 4.
XBMC is running smoothly, so I decided to add some work to my rapsberry and I installed Transmission and samba.
It worked fine for all day until tonight I decided to switch on the XBMC debug to try to solve a minor issue on library creation. Since then things went wrong. I normally connect via ssh to RPi to manage all but XBMC and if I type the command

df -h

as normal user or even as sudoer the RPi hangs and I have to remove power to unlock it.
Some help, please?
TIA
I posted the same issue here: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=28&t=30465