I just updated to from 10.6.0 to 10.6.3.

My notebook has 2 internal harddrives. The system one and one connected through an ultra-bay slim port.
I have a third external HDD attached via USB (also formatted with ntfs)
The second one contains one ntfs-partition.
I activated native write support for ntfs-files.

The second hdd was detected as a removable drive before updating.
Now it's detected as an internal drive, but when I open it in Finder it is empty.

Disk Utility shows up all stats as it should.

The external HDD is working perfectly.

If I create a new folder on the second HDD, it disappears in Finder after one second.

Does anyone have a clue what is going wrong?