[psidnell]

Boiled it down to this (which actually has no constraints it's the ALAP that's the issue I think):

This is a new project (using 2.1.1.) Add two tasks using Resource 1 and a milestone then wire it up thus:



Task 1 and Task 2 are scheduled ASAP by default, all is good, no violations.

Flip Task 1 & Task 2 to ALAP and:



I would have expected that both tasks would have shifted to the right a little, but not that they would overlap and conflict.

By adding a dependency from Task 1 to Task 2 the problem goes away: