I would say a combination of ISO and speed.
Site: DzR Photography
Flickr: Flickr
Camera: Sony A350 DSLR
Lenses: 18-70mm, 55-200mm, 50mm f1.4, 70-300G, Minolta 35-70mm f4, Tamron 17-50 2.8
Flash: Sony HVLF42AM
Tripod: 190xPROB, 488RC4
Memory: Sandisk Extreme 200x CF
Software: Adobe Photoshop CS3 + RAW
is it the af-d or af-s version of the lens? CA can be reduced with good coatings on lens glass. if lens coatings arent up to scratch then you get CA.
http://en.wikipedia.org/wiki/Chromatic_aberration
some astronomers use a minus violet filter to remove this, but i dont know what to do with a photographic lens.
What you can do is, in PS open HSL and drop the magenta, and similar colours, back to desaturate. If it wipes out other parts of you photo that you don't want messed with just apply a mask, invert and brush the areas you want fixed.