I have made a simple character model and am adding a skeleton to it, so i can use it as reference and so i can get a feel for how rigging and weight painting are.
The white box (Shoulder_L) has weight and is the one linked to the bone that's within it, however for some reason some vertices in the right arm move when i pose the shoulder, despite not having any weight.
(The area within the circle is where the vertex that moves is located)
Blend File