Error w/ Leaflet non-standard screen resolution

Question

I am not sure what the problem is, but this is a description of behavior and description of the problem:

1. I have two points and a track (it's all good now):

2. Change a scale of display (to simulate the behavior of the laptop with non-standard resolution)

3. Now it's problem time:

3.1. Both points remain in place, but the track moved out, and each time shifting it in any direction it will move.

I still use Leaflet v0.7.3

Anyone know what's the problem is?