I have the same problem. But unfortunately couldn't umount my usb either with umount ....
In my case the problem is Beagle. That for some reason runs on the devices. Here is what works for me:
This will list all processes running on usbdisk: sudo lsof | grep /media/usbdisk
The output in my case is: beagled-h 6160 nasos 48r REG 8,17 192000 54791 /me......
Next I kill beagled - helper (proccess 6160 in here) :
sudo kill -9 6160
and then I just unmount.
sudo umount /media/usbdisk
I don't know what effects to beagle this might have.
I have the same problem. But unfortunately couldn't umount my usb either with umount ....
In my case the problem is Beagle. That for some reason runs on the devices. Here is what works for me:
This will list all processes running on usbdisk:
sudo lsof | grep /media/usbdisk
The output in my case is:
beagled-h 6160 nasos 48r REG 8,17 192000 54791 /me......
Next I kill beagled - helper (proccess 6160 in here) :
sudo kill -9 6160
and then I just unmount.
sudo umount /media/usbdisk
I don't know what effects to beagle this might have.