Originally Posted by Lurker
Perhaps your load speeds are slow, either from router or ISP issues. If your initial page is still loading when you submit your solve, it may add those extra couple of seconds while it redirects. I'm suggesting this because you specifically have this problem with quick solves and not all of them.
Lurker, that's a great point! I guess it's quite possible that a super-fast solve would be done before the puzzle page is even fully loaded.