Is it just my computer?

I have GLSL shading on and Textured Shading checked. Viewport shading is set to Textured, and all the UV mapping is working right, but in the view, this is what I see. It’s all weird and chunky, with not even a passing resemblance to the actual normal map. Ideas? To clarify, the image is fine when I render, but I’m about to do some painting on this model, and I’d like it to display properly in the viewport.

OK, I’ve answered the question I asked on my own, but I guess it’s not the question I should have asked. Obviously it is my computer, because those texture artifacts aren’t even texture artifacts. If I zoom in close enough, it turns out to be my Twitter account that I had open about a half hour ago, upside down, tiled. The question I should have asked is “How do I make it go away?” I know if I use a lower resolution image as my UV texture, that solves the problem, but I’m using a high res image for a reason. This needs to stand up to closeups.

Looks strange, are the textures a power of 2? (10241024,20482048…etc.)

Yeah, the ones giving that result are I think 8192. Lower gets the correct results. I suspect I could solve this and many other problems by breaking down and buying a lot more memory. Maybe next week after payday.