I get this (correct) information by right clicking the partition in KDE and selecting properties:
Data: 0 Files, 2 Subfolders
sudo ls -al /media/data
drwxrwxrwx 4 root root 4096 2007-05-18 13:41 .
drwxr-xr-x 8 root root 4096 2007-05-19 08:35 ..
drwx------ 2 root root 4096 2007-05-18 17:12 lost+found
drwx------ 3 root root 4096 2007-05-18 13:41 .Trash-0
Yes... rt-click partition in KDE correctly shows you two folders and no files... ls -l also shows two folders and no files, so this must be correct too right?
I didn't reformat this drive, only the dedicated linux partition.
... please excuse me, scd4 is also a dedicated linux partition (according to your fdisk -l output anyway)... I take it you mean you reformatted linux root partition prior to, or as part of, the installation of feisty. OK.
The fact you can see the dummy file in /media/data shows there is nothing in the partition setup preventing you from seeing files in there.
This occurred after a clean installation and you did not restore anything to the data partition. The file data is visible to du as root, but not ls.
I suppose you could try sudo konqueror /media/data or ls at a root prompt (sudo su - ).
sudo chown -R <you> /media/data
 which is not possible, as written, BTW. I'm guessing you browse to /media in konqueror and rt-click the "data" folder icon. Or do you mean you browse to /dev and rt-click the "sdc4" block special device icon? But I digress.