problems with multitexturing and lines

Hi all.
I’m drawing some triangles using multitexturing (one 2D-texture and one 1D-texture). When I try to render some antialiased lines (with texturing disabled of course) my framerate drops (from 60) to 1 fps. When i don’t use multitexturing, there’s no problem with antialiased lines, and when I don’t use antialias lines there’s no problem with multitexturing. So the problem on occurs when they’re used together.

Anyone know what’s wrong?

// Thanks in advance, Ankan