Explode modifier on keyed particle systems issue

Hello,

I’m trying to make a keyed particle system with explode modifier on the two sets of words. It appears to work, but there are particles that appear out of thin air and other that appear out of order. I’m using a texture ramp to control the explosion and assembly from left to right. I think what is happening is there are some polys that are in the wrong index order so when they are trying to sync they are pulled from various locations.

Does anyone know how to fix this??? You’ll see the green particles appearing from nowhere.

Thanks
James