Really weird skinning problems.

Ok look: I’m preparing a model for a source engine, so there’s two bones with their own influence area. When i begin subtract area on one of them, this exactly area appears on another with more radius! How can it be?

It happening only with that jacket i imported from xnalara.

Blend file

Try to erease weights on her shoulder, then choose next arm bone and you will see it.

The brush has auto normalize on which causes it.

Use the compress feature in save as dialog when preparing files for upload. With this one it takes 2/3 off the file size with one click.