Solid broken line with antialiasing

I’m porting some 2D engine under OpenGL and want to use antialiased lines. But in joint points there is a “halo” and the broken line looks like its damaged. Turning of antialiasing kill this halo, but the line looks terrible.
Where does this side effect comes from? Did I wrong blending flags?

Did you follow these recommandations :

Apparently, it can depend a lot from the hardware :

Thanks for the hint.
It seems that I need to disable depth buffer update. I’ll try it as soon as I get home from the job ;]
10x again.