Viewport Backround Image Errors (2.49 and 2.50)

I’m trying to model a car from blueprints (a Ferrari), using the blueprints as background images in my viewports (front, back, top, left side).

I’ve adjusted the images so that they’re properly aligned, but I get some strange errors in the images that aren’t present in the source image.

It seems like some parts of the image are ‘skipped’, leaving visible seams in parts of the image. Also, the images seem very noisy.

The included image shows a side-by-side comparison, from Blender 2.5 Beta 0 on the left, and Gimp on the right. Notice the ‘seam’ running down the middle of the Blender image.

This happens on all the images, which are .tga’s between 1000 and 3500 pixels in dimension, and between 240kb and 1.5mb in size. Both Blender versions I’ve tested (2.49b, and 2.5) show these issues.

So, is this a bug, or is there something I can do to fix this?