Canon Japan release TWAIN drivers v2.4
New TWAIN drivers for the Powershot Pro70, A5, A5Zoom, A50 and 350.
The Japanese page makes some mention of white balance correction between CCDRAW and JPEG mode, however in my tests I have not observed any noticeable improvement of the white balance problem. The drivers do seem to make a "double pass" at CCDRAW decoding.
WARNING: These are Japanese drivers which use the Windows Japanese characater set, although they are usable you will NOT be able to read labels on dialog boxes or buttons. I would guess if you wait a week or so the English drivers will be out on www.powershot.com
If, like me you always want the latest drivers you can download them from here: (3 files)
Powershot Japanese TWAIN driver for Win95/98/NT4.0 Ver 2.4.0