Hm, since it's been a day I'm gonna follow up my own question with something a bit more broad:
Does anyone use the open.py script in the "System" Macros folder?
Can anyone confirm that it's supposed to work with FontLab 5?
As far as I understand, FontLab should execute this script when the application is launched, so if anyone wants to test the open.py and save.py you can just put a simple print statement in them like I mentioned in the last post and see if anything happens (only the save.py works for me)
Much appreciated,
Andy