I'm not a regular user of ubuntu, but seeing as no one else has replied...
Maybe the problem is not having the right tools installed for k3b to do the job. Check synaptic for vcdimager and vcdtools.
This method should work and is probably less confusing than using k3b;
1) Open synaptic and get vcdimager, cdrdao, and vcdtools.
2) Pop in the vcd
3) open a terminal and enter the command
if all goes well the ripping should begin, the prompt will return when it's done. If more than one drive you may need to try both. There should be files mpeg and xml now in the working directory. The .mpeg is directly playable in most players.
will create .cue and .bin files in the working directory
cdrdao write --device /dev/hdc videocd.cue
will burn the disk. videocd is a default name. /dev/hdc may not be correct in your case
to see what your disks are labelled
This can probably all be done through k3b as well. Also other ways available , never only one method in linux
Just throwing the above out as a method I use. Note my vcds are all of the home-made variety, commercial vcds may be another kettle of fish.
Do you happen to have 2 optical drives? Copying directly should be a possibility.