GL rendering problem.

In the first picture (Img A) you see the blending of the line correctly, but as soon as another line is created the blending is no longer applied (Img B).

This is a modified version of the 'Bullet Tracers' resource located here

if (mDataBlock->tracerLength > 0) 
   {
          Point3F end = mCurrVelocity;
	  end.normalize(mClampF((mCurrPosition - mInitialPosition).len(), 1.0, mDataBlock->tracerLength));	  
	  
	  // Make sure we have a width no matter what.
	  F32 tracerWidth = mDataBlock->tracerWidth;
	  tracerWidth > 0 ? tracerWidth : 0.1f;
	  glLineWidth(tracerWidth);
	  
	  glEnable(GL_BLEND);
	  glBegin(GL_LINES);
	  	
          // Start..
	  glColor4fv(mDataBlock->tracerStartColor);      
          glVertex3fv(mCurrPosition);
   
	  end = mCurrPosition - end;
	  glColor4fv(mDataBlock->tracerEndColor);	  
	  glVertex3fv(end);	  
	  // End..
	  	        	    
	  glEnd();
	  glDisable(GL_BLEND);
   }

Img A
Img B
What seems to be the issue with this? Do I need to disable anything in particular or vise-versa?