You aren't the first person to have this happen after trailering the bike. If you have the same issue after just letting the bike sit overnight, however, I'd suggest those lifters you bought aren't the greatest. You didn't mention your stock lifters doing this, and Harley's "C" lifters are far from the best in this regard. As Don noted in a previous post, the heavy valve springs in a 110 can lead to a lifter leaking down quicker, but all four valves aren't going to be off their seats at the same time. One lifter having to pump up is noisy for a short time, all the lifters having to pump back up at the same time might scare the bejesus out of you the first time it happens and it's not normal or good.
Jerry