i've a VIA Epia C3 mini server running Debian 6.0. I also have an external EXT4 500 gb Hard disk connected via USB 2.0. The problem is that sometimes (a lot of times), the hard disk automatically unmount itself, then is remounted in different location. So, for example, it is mounted in /media/MyHardDiskName ... then it auto remount in /media/MyHardDiskName_
It is a strange beahviour!