According to DPreview:
Canon has released a firmware update for the PowerShot G10 compact camera. Version 1.0.2.0 rectifies the occurrence of a magenta cast when RAW images are captured at ISO 1600 in continuous shooting mode or in single shooting mode with the monitor switched off. The fix only affects cameras with a serial number within a range specified by Canon.
For details see:
http://web.canon.jp/imaging/dcp/firm-e/psg10/index.htmlAs I'm never going to use mine above ISO 400 this won't ever be a problem
Paul