Not impossible at all. You do have to have the app open as the foreground app, of course.
I don't know why you say such things. It's easily verifiable behavior, and I just verified it in the current version on my iPod Touch. If you switch away, it starts a sync. The periodic syncs take place if you have the app open and have internet connectivity. If you don't have the app running in the foreground, well, that's your problem, not mine.
It does appear that if you didn't have it running in the foreground at the time a sync was due, no immediate sync is launched upon bringing it to the foreground, and that seems like an opportunity for improvement.
If you still don't believe that it syncs after a switch, take it up with Ken:
http://forums.omnigroup.com/showpost...5&postcount=25