Hello,
I am newbie to k3b.

What is the procedure for burning multiple times with RW DVD media (4.7 GB)?
I mean:
after Tools->burn image ->
should I select: Advanced->Start multisession CD ?
because I burned such a RW Media without marking this checkbox, and after
some time when I inserted it again for a second time of burning, it said:
"Please insert empty DVD or Blu-ray medium"

regards,
DavidS

It depends on what you want to do. Do you wish to simply add more data to the disc, or do you want to remove everything on it and replace those contents with something else?