CD/DVD CREATOR doesn't work in fedora 7

[Jan Brosius]

Hi,

I have installed fedora 7 (64 bit)

  When I try to burn something with CD/DVD Creator a second time on the 
same rewritable dvd rw disc (after burning something on this disc) I get 
the following error message:
There was an error writing to the disc: The target DVD drive is still in
use.

  I also installed k3b. The first time I
can write a file successfully to a dvd RW disc. But afterwards when I
try to add a file to this dvd disc it fails giving me the following
error messages

- :-(/dev/sdc0: unable to proceed with recording: unable to unmount
- Fatal error at startup: Device or resource busy
- unable to eject media

But before these error I get the following messages:
- Waiting for media
- Writing DVD-RW in incremental mode.
- Unmounting disk
- Searching previous session
- Using growsisofs 7.0 - Copyright (C) Andy Polyakov ..
- Unmounting medium
- Starting disc write ...


Can someone tell me what to do?

Thanks for any help
Jan