I have been trying to set up a floating point texture and keep getting 1281 errors back when I try it. Here is on of several things I have tried:

glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_R32_NV, 256, 256, 0, GL_FLOAT_R_NV, GL_FLOAT, data);

I am using a GeForce FX 5900 and the extension is being reported as available in the extension string.

What do I need to do to get it working?

Use GL_R as format parameter

Ok, got it working, thanks