Am I wrong or to make autosave/load work I must put a pause of 500ms before it?

Yeah, it needs a pause because the  scene needs to be loaded before saving it - Doesn't necessarily have to be 500ms. There are a few action parts that won't be executed if you try adding them inside of an at begin of scene action block without a small pause at the beginning of the action block - but I can't remember what they are off the top of my head - in general it's best to pause for at least the amount of time it takes to fade into the scene which by default is about 600ms.

it depends in where you set it. I have no problems with the autosave in a custom system. 

Thank you guys.