please help with mounting usb stick again (after mount screwup)

[Sharky444]

My intention was to link /mnt/usbdrive to /sdcard/usb on my galaxy tab 10.1 with cm10 preview.

Creating a symlink using ln -s did not work, because the stick is fat32.

So I've googled some more and found this "solution":

mount -o /olddir /newdir

so I've executed:

mount -o /mnt/usbdrive /sdcard/usb

and it worked! I could see the content of the usb stick in /sdcard/usb.

my joy was not long.

I've discovered that after removing and reinserting the usb stick,
it was not mounting correctly anymore. both /mnt/usbdrive and /sdcard/usb
were just empty folders.

So I've tried restoring the old state with this:

umount /storages/sdcard0/usb

this worked without error, and I've also deleted the /sdcard/usb folder.

I've reinserted the stick, but /mnt/usbdrive is still an empty folder!

what's worse - geoing to settings | storage in CM10 results in a settings app crash!

If I type mount (as super user) I get this as the last line:

/dev/block/vold/8:0 on /mnt/usbdrive type vfat (rw,...)

but doing a ls /mnt/usbdrive shows it's empty.

I've attached the usb stick to a Windows notebook, and the files are still there.

Please help me to restore the old state and get the usb stick working again!