Don't say to continue anyway - unless you've explicitly been told by the manufacturer that it's okay. Most of the time if something hasn't passed the XP compatibility test it will screw up your system. The last time I said "yeah, go ahead with it anyway" my system wouldn't boot and I had to re-install XP.
Look around for an updated driver. Another idea is to get a reader for your compact flash or smart media (whichever one your camera uses). The readers hook up via USB and there are many available for XP. They show up as a drive on your system in Windows Explorer.