While Patchou is on holidays could you test something for us.
Create a script on Computer A. Copy the following code into the script.
js code:
function OnEvent_MyPsmChange ( sNewPsm )
{
Debug.Trace ( sNewPsm );
}
Reproduce the bug. The purpose of this is to see if the Plus! event fires when the PSM is changed on Computer B. This will help Patchou resolve the bug.