Just ignore that warning.
I had tested it last night. Whenever you place a positron, the game will get extremely laggy, to the point of getting about 1 frame every 7-10 seconds. It's better than it used to be (where the game would permanently freeze), but it's still not working properly.
Yeah, I think that's the same one that you had posted on page 12 of this thread. I just tested it again and it does the same thing; the game freezes for a few seconds at a time once a positron is placed. It might just be on my end, though, so I'd rather see what other people have to say about the positron's performance.
probably not your OS, i am using WinXP and it is working fine.