This might sound silly, but did you set your ghost off? (I can't tell if those are just trails, not the ghost) -Press G-
The spar timer is usually set to a slow reaction, and if the person is not available for a long period you most likely lose connection or end up waiting for him to finish. Do you play any other mods? Try to do some quick mods and see how it works for you. Oh, and be sure your spar partner is pressing space and not doing something else, that might be the best explanation for your problem.