I also did this (some time ago), it was easier just to add a second swap partition instead of attempting to resize the existing one. Knoppix will find and use both swap partitions. QTparted will only work on a drive which is not in use so the resizing is easiest done running from CD, you will have to 'noswap' so that the HD is not in use.
I have also added a dos swap file which works just fine as an addition to the regular swap partition.