Red Color Shift

Forgive the lack of pics to post that would illustrate my point. I'm working on getting some up. Anyway, I was at Laguna Seca raceway in Monterey, CA for the MotoGP motorcycle race this past week. I took many photos of bikes both on the track and in the paddock area. I noticed a disturbing trend in my pictures that contained red bikes (Ducati and Honda bikes in particular) - the reds were far too purple in cast. I used RAW+JPEG (RAW in PEF format) and both the unprocessed RAW and JPEGs had the same issue. I used Aperture to post-process and had to significantly change the red hue to bring the pictures to normal red color rendition.

The settings on my camera were auto white balance (5000k in the EXIF data), "bright" mode and no other weirdness. The day was overcast in the morning but evenly illuminated (typical Monterey marine layer until about 2:00 in the afternoon). In the paddock area Honda had their tents which have translucent white nylon tops over their bikes. The matting was red beneath the work area and their trucks were typical Honda red with black accents. The superbikes were all red and the MotoGP bikes of the Repsol livery had lots of red in decals as well. ALL of the red was off-hue no matter whether under cover or not. I was able to adjust using hue controls in Aperture, but I shouldn't have to do that under normal daylight and auto white balance (although adjusting white balance in post did not correct the problem - i tried just to see).

Anyone else experience this? Recommendations?

Chuck