PowerShell Set-PSBreakpoint bug in PowerShell 3_

I found a very annoying problem in PowerShell 3

It does not stop on breakpoints if new PowerShell process is created.

It was fine in PowerShell 2

Steps to reproduce:

Create MyScript.ps1 with the following content

function MyFunction()
{
    Write-Host "Breakpoint should be hit"
}

Set-PSBreakpoint -Command MyFunction | Out-Null

MyFunction

And create MyScript.cmd with the following content

@echo off

echo PowerShell 2 stops on breakpoint PowerShell -Version 2 .\MyScript.ps1

echo PowerShell 3 does not stop on breakpoint PowerShell -Version 3 .\MyScript.ps1

Then run MyScript.cmd. You will see that when we run script in PowerShell 2 mode, it stops on the breakpoint we set. But this is not happening in PowerShell 3.

I could not find any explanations of that.

I found slightly similar bug: PowerShell V3 breakpoint bug

EDIT: Raised a bug for Microsoft, please vote for it https://connect.microsoft.com/PowerShell/feedback/details/767381/powershell-3-set-psbreakpoint-is-not-working-accross-different-powershell-exe-processes